JP7234132B2 - Regioselectively substituted cellulose ester - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to the fields of cellulose chemistry, cellulose ester compositions, methods of making cellulose esters and films made from cellulose esters.

BACKGROUND OF THE INVENTION Cellulose is a β-1,4-linked polymer of anhydroglucose. Cellulose is typically a high molecular weight, polydisperse polymer that is insoluble in water and virtually all common organic solvents. The use of unmodified cellulose in wood or cotton products such as housing or textiles is well known. Unmodified cellulose is also commonly used in a variety of other applications as films such as cellophane, fibers such as viscose rayon, or powders such as microcrystalline cellulose used in pharmaceutical applications. Modified celluloses such as cellulose esters are also widely used in a wide variety of commercial applications. Prog. Polym. Sci. 2001, 26, 1605-1688. Cellulose esters are generally prepared by first converting cellulose to cellulose triesters and then hydrolyzing the cellulose triesters to the desired degree of substitution in an acidic aqueous medium. Hydrolysis of cellulose triacetate under these conditions produces random copolymers that can be composed of eight monomers depending on the final degree of substitution. Macromolecules 1991, 24, 3050.

This application describes novel regioselectively substituted cellulose esters prepared by first treating cellulose with trifluoroacetic anhydride in trifluoroacetic acid and then adding an acyl donor or acyl donor precursor. will be explained.

SUMMARY OF THE INVENTION The present application discloses regioselectively substituted cellulose esters comprising:
(i) multiple R ¹ -CO-substituents, and (ii) multiple hydroxyl substituents,
wherein the degree of substitution of R ¹ -CO- at the C2 position (“C2DS _R1 ”) ranges from about 0.2 to about 1.0;
the degree of substitution of R ¹ -CO- at the C3 position (“C3DS _R1 ”) ranges from about 0.2 to about 1.0;
the degree of substitution of R ¹ —CO— at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.5;
the hydroxyl degree of substitution ranges from about 0 to about 2.6;
R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (hetero is non- substituted or substituted with 1 to 6 R ³ groups;
R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 ) aryl or nitro, and R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo , (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

The present application also discloses regioselectively substituted cellulose esters including:
(i) a plurality of R ¹ -CO-substituents;
(ii) a plurality of R ^-CO -substituents;
(iii) multiple hydroxyl substituents;
wherein the degree of substitution of R ¹ -CO- at the C2 position (“C2DS _R1 ”) ranges from about 0.2 to about 1.0;
the degree of substitution of R ¹ -CO- at the C3 position (“C3DS _R1 ”) ranges from about 0.2 to about 1.0;
the degree of substitution of R ¹ —CO— at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.5;
the degree of substitution of R ^-CO- at the C6 position ("C6DS _R4 ") ranges from about 0.1 to about 1.0;
the hydroxyl degree of substitution ranges from about 0 to about 2.6;
R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (hetero is non- substituted or substituted with 1 to 6 R ³ groups;
R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 ) selected from aryl or nitro;
R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 ) selected from aryl or nitro;
R ⁴ is (C _1-20 )alkyl, halo(C _1-5 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1 to 6 R ⁵ groups), or a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl is unsubstituted or substituted with 1 to 6 R ⁶ groups;
R ⁵ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 ) aryl or nitro, and R ⁶ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo , (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

The present application also discloses films made from the regioselectively substituted cellulose esters disclosed herein. The present application also discloses methods for preparing the regioselectively substituted cellulose esters disclosed herein.

DETAILED DESCRIPTION In this specification and the claims that follow, a number of terms are referenced and defined to have the following meanings.

The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

Values can be expressed as "about" or "approximately" a specified number. Similarly, ranges can be expressed herein as from "about" one particular value, and/or to "about" or another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations using the antecedent "about," it is understood that the particular value forms another aspect.

Optical films are generally quantified in terms of birefringence, which is related to the refractive index n. The refractive index typically ranges from 1.4 to 1.8 for polymers in general and can be about 1.46 to 1.50 for cellulose esters. The higher the refractive index, the slower the light wave propagates through that given material.

For an unoriented isotropic material, the refractive index will be the same regardless of the polarization state of the incident light wave. When the material is oriented or otherwise anisotropic, the refractive index becomes dependent on the direction of the material. For the purposes of this invention, there are three refractive indices of interest, designated _nx , _ny and _nz , respectively in the machine direction ("MD"), transverse direction ("TD") and thickness direction. handle. As the material becomes more anisotropic (eg, by stretching), the difference between the two refractive indices increases. This difference is called "birefringence". Since there are many combinations of material orientation choices, the birefringence values will vary accordingly. The two most common, plane birefringence (or “in-plane” birefringence) Δ _e and thickness birefringence (or “out-of-plane” birefringence) Δ _th are defined as follows.

(1a) Δ _e =n _x -n _y
(1b) Δ _th =n _z -(n _x +n _y )/2

The birefringence Δ _e is a measure of the relative in-plane orientation between the MD and TD directions and is dimensionless. In contrast, Δ _th provides a measure of through-thickness orientation relative to average planar orientation.

Another term often used for optical films is optical retardation R. R is simply the birefringence times the thickness d of the film of interest. therefore,

(2a) R _e = Δ _e d = (n _x - n _y ) d
(2b) R _th =Δ _th d=[n _z −(n _x +n _y )/2]d

Retardation is a direct measure of the relative phase shift between two orthogonal lightwaves and is typically reported in nanometers (nm). Note that the definition of R _th varies from author to author, depending on how R _th is calculated, especially with respect to the sign (+/-).

Materials are also known to vary with respect to their birefringence/retardation behavior. For example, most materials, when stretched, exhibit a high refractive index along the stretching direction and a low refractive index perpendicular to stretching. This is because, at the molecular level, the refractive index is typically higher along the axis of the polymer chain and lower relative to perpendicular to the chain. These materials are commonly referred to as "positively birefringent" and represent most standard polymers, including cellulose esters, currently commercially available. Note that positively birefringent materials can be used to create positively or negatively birefringent films or waveplates, as described below.

To avoid confusion, the birefringent behavior of the polymer molecule itself is called "intrinsic birefringence" and is a property of polymers. From the point of view of material optics, intrinsic birefringence is a measure of the birefringence that occurs when a material is fully stretched with all chains perfectly aligned in one direction (for most polymers, perfect alignment This is a theoretical limit, since you cannot.) For purposes of the present invention, it also provides a measure of the sensitivity of a given polymer to a given amount of chain orientation. For example, a sample with high intrinsic birefringence will exhibit greater birefringence during film formation than a sample with low intrinsic birefringence, even at approximately the same relative stress level within the film.

Polymers can have positive, negative, or zero intrinsic birefringence. A polymer with negative intrinsic birefringence exhibits a higher refractive index in the direction perpendicular to the draw direction (versus the parallel direction). Certain styrenic and acrylic resins can have negative intrinsic birefringence behavior due to rather bulky side groups. Depending on composition, some cellulose esters with aromatic ring structures can also exhibit negative intrinsic birefringence. In contrast, zero intrinsic birefringence is a special case and represents a material with zero intrinsic birefringence as it exhibits no birefringence upon stretching. Such materials may be ideal for certain optical applications because they can be shaped, stretched, or otherwise stressed during processing without exhibiting optical retardation or distortion.

The actual compensation films used in LCDs are biaxial films where all three refractive indices are different and there are two optic axes, and only one optic axis where two of the three refractive indices are the same. It can take a variety of forms, including uniaxial films with ridges and the like. There are also other classes of compensation films in which the optic axis is twisted or tilted through the thickness of the film (eg, discotic films), but these are generally less important. In general, the types of compensation films that can be made are limited by the birefringence properties of the polymer (ie, positive, negative, or zero intrinsic birefringence). The symbol can be placed before or after the film type (eg +A or A+). Some examples are given below.

In the case of uniaxial films, films with indices of refraction as follows are designated as "+A" optical films.
(3a) n _x >n _y =n _z "+A" optical film In such a film, the x-direction (machine direction) of the film has a high refractive index and the y-direction and thickness direction are approximately the same size. (and less than _nx ). This type of film is also called a positive uniaxial crystal structure with the optic axis along the x-direction. Such films can be made by uniaxially stretching a material of positive intrinsic birefringence using, for example, a film stretcher.

In contrast, a "-A" uniaxial film is defined as follows.
(3b) n _x <n _y = n _z “-A” optical film

Here the refractive index in the x-axis is lower than in the other directions (they are approximately equal). -A One method for making optical films is to stretch polymers of negative intrinsic birefringence or to align the molecules in preferred directions (e.g., using an underlying etched alignment layer). and) coating the surface with a negative (intrinsic) birefringent liquid crystal polymer.

With respect to retardation, the "±A" optical films have the following relationship between R _e and R _th (3c).
(3c) R _th =−R _e /2 “±A” optical film

Another class of uniaxial optical films is the C optical films, which can also be "+C" or "-C." The difference between C and A optical films is that in C optical films the inherent refractive index (or optic axis) is in the thickness direction rather than in the plane of the film. therefore,

(4a) n _z >n _y =n _x “+C” optical film (4b) n _z <n _y =n _x “−C” optical film

C optical films can be made using the stresses that occur during solvent casting of the film. Tensile stress is generally created in the plane of the film due to the restraint imposed by the casting belt. It is also essentially equibiaxially oriented. These tend to align the chains in the plane of the film, resulting in −C or +C films for positive and negative intrinsic birefringence materials, respectively. Since many cellulose ester films used in displays are solvent-cast and many are positively birefringent in nature, it appears that solvent-cast cellulose esters typically produce only -C optical films. is. These films can also be uniaxially stretched to make +A optical films (assuming very low initial casting delay).

Besides uniaxial optical films, biaxially oriented films can also be used. Biaxial films are quantified in a variety of ways, including simply listing the three indices of refraction n _x , _ny and _nz in the principal directions (along the direction of these principal axes). In general, n _x ≠ _ny ≠ _nz .

Certain biaxially oriented films have unique optical properties that compensate for light leakage in a pair of crossed polarizers or in-plane switching (“IPS”) mode liquid crystal displays. The optical film has a parameter _Nz in the range of about 0.4 to about 0.9, or equal to about 0.5, where Nz is defined as follows.

(5) N _z = (n _x -n _z )/(n _x -n _y )

This parameter provides the effective out-of-plane birefringence versus in-plane birefringence. _Nz can be chosen to be about 0.5 when used as a compensation film for a pair of crossed polarizers. When N _z is about 0.5, the corresponding out-of-plane retardation R _th is equal to about 0.0 nm.

To show the compensation effect of the optical film, the light transmittance or leakage of a pair of crossed polarizers with and without the compensation film is calculated by computer simulation below.

"Degree of substitution" means the average number of substituents per anhydroglucose monomer of the cellulose ester. Degree of substitution can refer to substituent groups, such as acyl groups, attached to the anhydroglucose monomer. Degree of substitution can also refer to the number of free hydroxyl groups on the anhydroglucose monomer. The degree of substitution can specify the position on the anhydroglucose monomer. For example, the degree of substitution can be applied to the C2, C3 or C6 positions of the anhydroglucose monomer (eg, C2DS, C3DS, C6DS).

Alternatively, the degree of positional substitution can be expressed by indicating the position before the term "degree of substitution" (eg, C2 degree of substitution or C2 and C3 combined degree of substitution).

By "degree of polymerization" is meant the number of glucose units that make up one polymer molecule.

Regioselectively substituted cellulose esters suitable for use in making optical films can contain multiple alkyl-acyl substituents and multiple aryl-acyl substituents. As used herein, the term "acyl substituent" refers to the structure:

を有する置換基を表す。

represents a substituent having

Such acyl groups in cellulose esters are generally attached to the pyranose ring of cellulose through an ester bond (ie, through an oxygen atom).

As used herein, the term "alkyl-acyl" represents an acyl substituent where "R" is an alkyl group. Often carbon units of alkyl groups are included, eg (C _1-6 )alkyl-acyl. Examples of alkyl-acyl groups include acetyl, propionyl, butyryl, and the like.

As used herein, the term "alkyl" represents a hydrocarbon substituent. Alkyl groups suitable for use herein can be straight, branched or cyclic, and can be saturated or unsaturated. Carbon units in alkyl groups are often included, eg, (C _1-6 )alkyl. Alkyl groups suitable for use herein include any (C _1-20 ), (C _1-12 ), (C _1-5 ) or (C _1-3 ) alkyl group. In various embodiments, alkyl can be a C _1-5 straight chain alkyl group. In still other embodiments, the alkyl can be a C _1-3 straight chain alkyl group. Examples of suitable alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl. , cyclopentyl and cyclohexyl groups.

The acylating agent can be any known in the art for acylating cellulose to form cellulose esters. In one embodiment of the invention, the acylating reagent is one or more C ₁ -C ₂₀ straight or branched chain alkyl or aryl carboxylic acid anhydrides, carboxylic acid halides, diketenes or acetoacetates. Examples of carboxylic anhydrides include, but are not limited to, acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, hexanoic anhydride, 2-ethylhexanoic anhydride, nonanoic anhydride, Lauric anhydride, palmitic anhydride, stearic anhydride, benzoic anhydride, substituted benzoic anhydride, phthalic anhydride and isophthalic anhydride. Examples of carboxylic acid halides include, but are not limited to, acetyl, propionyl, butyryl, hexanoyl, 2-ethylhexanoyl, lauroyl, palmitoyl, benzoyl, substituted benzoyl and stearoyl halides. Examples of acetoacetates include, but are not limited to, methylacetoacetate, ethylacetoacetate, propylacetoacetate, butylacetoacetate and tert-butylacetoacetate. In one embodiment of the invention, the acylating reagent is at least one C ₂ -C selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, 2-ethylhexanoic anhydride, nonanoic anhydride and stearic anhydride. ₉ is a straight or branched chain alkyl carboxylic acid anhydride. After the cellulose is dissolved in the tetraalkylammonium alkylphosphate, the acylating reagent can be added. If desired, an acylating reagent can be added to the tetraalkylammonium alkylphosphate prior to dissolving the cellulose in the tetraalkylammonium alkylphosphate. In another embodiment, the tetraalkylammonium alkyl phosphate and the acylating reagent can be added simultaneously to cellulose to produce a cellulose solution.

"Haloalkyl" means an alkyl substituent in which at least one hydrogen has been replaced with a halogen group. Carbon units in haloalkyl groups are often included, eg, halo(C _1-6 )alkyl. A haloalkyl group can be straight or branched. Non-limiting examples of haloalkyl include chloromethyl, trifluoromethyl, dibromoethyl, and the like.

"Alkenyl" means an alkyl group of at least 2 carbon units containing at least one double bond. Carbon units in alkenyl groups are often included, eg (C _2-6 )alkenyl. Alkenyl groups can be straight or branched. Non-limiting examples of alkenyl include ethenyl, allyl, 1-butenyl, and the like.

"Cycloalkyl" means cyclic alkyl groups having at least 3 carbon units. Carbon units in cycloalkyl groups are often included, eg, (C _3-8 )cycloalkyl. Non-limiting examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclohexyl, cycloheptyl, and the like.

"Aryl" means an aromatic carbocyclic group. Aryl groups may be monocyclic or polycyclic. A polycyclic ring system is considered aryl when one of the rings in the polycyclic ring system is aryl. In other words, not all carbocyclic rings in a polycyclic aryl group need be aromatic. Carbon units in aryl groups are often included, eg (C _6-20 )aryl. Non-limiting examples of aryl include phenyl, naphthalenyl, 1,2,3,4-tetrahydronaphthalenyl, and the like.

"Heteroaryl" means aryl in which at least one of the carbon units in the aryl ring has been replaced with a heteroatom such as O, N and S. Heteroaryl rings may be monocyclic or polycyclic. Often the units are included to make up a heteroaryl ring system, eg a 5-20 membered ring system. A 5-membered heteroaryl refers to a ring system having 5 atoms forming a heteroaryl ring. Non-limiting examples of heteroaryl include pyridinyl, quinolinyl, pyrimidinyl, thiophenyl, and the like.

"Alkoxy" means an alkyl group terminally bound to an alkyl-O- or oxygen group. Often carbon units are included, eg (C _1-6 )alkoxy. Non-limiting examples of alkoxy include methoxy, ethoxy, propoxy and the like.

"Haloalkoxy" means alkoxy in which at least one hydrogen has been replaced with halogen. Often carbon units are included, eg halo(C _1-6 )alkoxy. Non-limiting examples of haloalkoxy include trifluoromethoxy, bromomethoxy, 1-bromo-ethoxy, and the like.

"Halo" means halogen such as fluoro, chloro, bromo or iodo.

A "reverse A film" is a film that satisfies the following conditions. The in-plane retardation ranges from about 100 nm to about 300 nm when measured at 589 nm, R _e 450/R _e 550 is less than 1, R _e 650/R _e 550 is greater than 1, R _e 450 , R _e 550 and R _e 650 are the in-plane retardation values of the film when measured at wavelengths of 450 nm, 550 nm and 650 nm, respectively.

A "reverse NRZ film" is a film that satisfies the following conditions. The in-plane retardation (“R _e ”) ranges from about 100 nm to about 300 nm when measured at 589 nm, the out-of-plane retardation (“R _th ”) ranges from about −50 nm to about 0 nm, and the R _e 450/R _e 550 is less than 1 and R _e 650/R _e 550 is greater than 1, where R _e 450, R _e 550 and R _e 650 are measured at wavelengths of 450 nm, 550 nm and 650 nm respectively. This is the in-plane retardation value of the film when

A "NRZ film" is a film that satisfies the following conditions. We use an N _Z value of n _Z =(n _x −n _z )/(n _x −n _y )=0.5. Alternatively, use an R _th value of R _th =[n _z -(n _x +n _y )/2]*d=0. where n _x , _ny and _nz are the refractive indices of the film in the x, y and z directions, respectively, and d is the film thickness.

As used herein, the term "selected from" used with "and" or "or" has the following meaning: A variable selected from A, B and C means that the variable A alone , B alone or C alone. A variable A, B or C means that the variable is A alone, B alone, C alone, A and B in combination, B and C in combination, A and C in combination, or A, B and C in combination. do.

Cellulose esters prepared by the method of the present invention are useful in a variety of applications. Those skilled in the art will appreciate that the particular application depends on the particular type of cellulose ester, as factors such as the type of acyl substituent, DS, MW, and type of cellulose ester copolymer significantly affect the physical properties of the cellulose ester. will understand. Prog. Polym. Sci. 2001, 26, 1605-1688.

In yet another embodiment of the invention, cellulose esters are used for coating applications. Examples of coating applications include, but are not limited to, automotive, wood, plastic or metal coatings. Examples of preferred cellulose esters for use in coating applications include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate or mixtures thereof.

In yet another embodiment of the present invention, cellulose esters are used in applications involving solvent casting of films. Examples of these applications include photographic films and protective and compensation films for liquid crystal displays. Examples of preferred cellulose esters for use in solvent cast film applications include cellulose triacetate, cellulose acetate, cellulose propionate and cellulose acetate propionate.

In yet another embodiment of the invention, the cellulose esters of the invention can be used in applications involving solvent casting of films. Examples of such applications include photographic films, protective and compensation films for LCDs. Examples of cellulose esters suitable for use in solvent cast film applications include, but are not limited to, cellulose triacetate, cellulose acetate, cellulose propionate and cellulose acetate propionate.

In one embodiment of the invention, films comprising the cellulose esters of the invention are produced and used as protective and compensation films for LCDs. These films can be prepared by solvent casting as described in US Patent Application No. 2009/0096962 or by melt extrusion as described in US Pat. No. 8,344,134, both of which are described herein. To the extent not inconsistent with the description, it is incorporated in its entirety into the present invention.

When used as a protective film, the film is typically laminated to either side of an oriented iodinated PVOH polarizing film to protect the PVOH layers from scratches and moisture while also increasing structural rigidity. When used as a compensation film (or plate), the film can be laminated with a polarizer stack or otherwise contained between the polarizer and the liquid crystal layer. These compensation films can improve the contrast ratio, wide viewing angle and color shift performance of LCDs. The reason for this important feature is that typical crossed polarizer sets used in LCDs have significant light leakage along the diagonal (leading to low contrast ratio), especially at large viewing angles. . It is known that various combinations of optical films can be used to correct or "compensate" for this light leakage. These compensation films must have a specific, well-defined retardation (or birefringence) value, which depends on the type or mode of liquid crystal cell used. This is because the liquid crystal cell itself also imparts a certain degree of undesirable optical retardation that needs to be corrected.

Compensation films are generally quantified in terms of birefringence, which in turn is related to refractive index n. For cellulose esters, the refractive index is about 1.46-1.50. For an unoriented isotropic material, the refractive index will be the same regardless of the polarization state of the incident light wave. When the material is oriented or otherwise anisotropic, the refractive index depends on the direction of the material. For the purposes of the present invention, there are three refractive indices of interest, designated _nx , _ny and _nz , corresponding to the MD, TD and thickness directions respectively. As the material becomes more anisotropic (eg, by stretching), the difference between the two indices of refraction increases. This difference in refractive indices is called the birefringence of the material for the particular combination of refractive indices. Since there are many combinations of material orientation choices, there are correspondingly different values of birefringence. The two most common birefringence parameters are the planar birefringence, defined as Δ _e =n _x −n _y , and the thickness birefringence, defined as Δ _th =n _z −(n _x +n _y )/2. is the refraction (Δ _th ). The birefringence _Δe is a measure of the relative in-plane orientation between MD and TD and is dimensionless. In contrast, Δ _th provides a measure of through-thickness orientation relative to average planar orientation.

Optical retardation (R) _is related to birefringence by film thickness (d) _; R _{e =} Δ _e d=(n _x −n _y )d; _x +n _y )/2]. Retardation is a direct measure of the relative phase shift between two orthogonal lightwaves and is typically reported in nanometers (nm). Note that the definition of R _th varies from author to author, especially with respect to the sign (±).

Materials are also known to vary with respect to their birefringence/retardation behavior. For example, most materials, when stretched, exhibit a high refractive index along the stretch direction and a low refractive index perpendicular to the stretch. This is because, at the molecular level, the refractive index is typically higher along the axis of the polymer chain and lower perpendicular to the chain. These materials are commonly referred to as "positively birefringent" and represent most standard polymers including all current conventional cellulose esters.

To avoid confusion, the birefringence behavior of the polymer molecule itself is called "intrinsic birefringence" and is a property of polymers. From the point of view of material optics, intrinsic birefringence is a measure of the birefringence that occurs when a material is fully stretched with all chains perfectly aligned in one direction (for most polymers, perfectly aligned This is a theoretical limit, since you cannot.) For purposes of the present invention, it also provides a measure of the sensitivity of a given polymer to a given amount of chain orientation. For example, a sample with high intrinsic birefringence exhibits greater birefringence during film formation than a sample with low intrinsic birefringence, even at approximately the same relative stress level within the film.

Polymers can have positive, negative, or zero intrinsic birefringence. A polymer with negative (intrinsic) birefringence exhibits a higher refractive index in the direction perpendicular to the draw direction (versus the parallel direction) and consequently also has negative intrinsic birefringence. Certain styrenic and acrylic resins are known to have negative intrinsic birefringence due to their rather bulky side groups. Depending on the composition, some cellulose esters with aromatic ring structures also exhibit negative intrinsic birefringence. In contrast, zero intrinsic birefringence is a special case and represents a material with zero intrinsic birefringence as it exhibits no birefringence upon stretching. Such materials are ideal for optical applications because they can be shaped, stretched, or otherwise stressed during processing without exhibiting optical retardation or distortion.

The actual compensation films used in LCDs are biaxial films where all three refractive indices are different and two optical axes exist and two of the three refractive indices are the same and only one optical axis is present. It can take a variety of forms, including uniaxial films having a There are also other classes of compensation films in which the optic axis is twisted or tilted through the thickness of the film (eg, discotic films), but these are not critical to the understanding of the invention. Importantly, the types of compensation films that can be made are limited by the birefringence properties of the polymer (ie, positive, negative, or zero intrinsic birefringence).

Compensation films or plates can take many forms depending on the mode in which the LCD display device operates. For example, a C-plate compensation film is isotropic in the xy plane and the plate can be positive (+C) or negative (-C). For a +C plate, n _x = _ny < _nz . For the −C plate, n _x =n _y >n _z . Another example is an A-plate compensation film that is isotropic in the yz direction. Again, the plates can be positive (+A) or negative (-A). For the +A plate, n _x >n _y =n _z . For the −A plate, n _x <n _y =n _z .

Generally, aliphatic cellulose esters provide R _th values ranging from about 0 to about −350 nm at a film thickness of 60 μm. The most important factors influencing the observed R _th are the type of substituents and the DS _OH . Films made using very low DS _OH cellulose mixed esters had R _th values ranging from about 0 to about -50 nm. U.S. Pat. No. 8,344,134. It was shown that significantly increasing the DS _OH of the cellulose mixed esters resulted in larger absolute values of R _th in the range of about -100 to about -350 nm. U.S. Patent Application Publication No. 2009/0096962. Cellulose acetate typically provides R _th values ranging from about -40 to about -90 nm depending on DS _OH .

To obtain the desired _Re value using the cellulose esters of the present invention, the film must be stretched. Desired R _e and R _th can be achieved by adjusting stretching conditions such as stretching temperature, stretching type (uniaxial or biaxial), stretching ratio, preheating time and temperature, and post-stretching annealing time and temperature. The exact stretching conditions will depend on the specific composition of cellulose ester, the amount and type of plasticizer, and the glass transition temperature of that particular composition. Therefore, the specific drawing conditions can vary widely. The stretching temperature can range from 140°C to 190°C. The draw ratio can range from 1.0 to 1.3 in the machine direction (MD) and from 1.1 to 1.8 in the TD. The preheating time can range from 10 to 300 seconds and the preheating temperature can be the same as the stretching temperature. The post-annealing time can range from 0 to 300 seconds and the post-annealing temperature can range from 10° C. to 40° C. below the stretching temperature. The thickness of the film depends on the thickness of the film before stretching and the stretching conditions. After stretching, the preferred film thickness is from about 10 μm to about 200 μm. More preferred is when the thickness of the film is from about 20 μm to about 100 μm. Even more preferred is when the thickness of the film is from about 25 μm to about 70 μm.

Regioselectively Substituted Cellulose Esters The present invention discloses regioselectively substituted cellulose esters comprising: (i) multiple R ¹ -CO-substituents, (ii) multiple hydroxyl substituents. , wherein the degree of substitution of R ¹ -CO- at the C2 position (“C2DS _R1 ”) ranges from about 0.2 to about 1.0, and the degree of substitution of R ¹ -CO- at the C3 position ( “C3DS _R1 ”) ranges from about 0.2 to about 1.0, and the degree of substitution of R ¹ —CO— at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.5. , the degree of hydroxyl substitution ranges from about 0 to about 2.6, and R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _{3- 7} ) cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1 to 6 R ² groups), or 1 independently selected from oxygen, sulfur and nitrogen is selected from 5-20 membered heteroaryl containing ~3 heteroatoms (heteroaryl is unsubstituted or substituted with 1-6 R ³ groups) and R ² is (C _1-6 ) alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro is selected and R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl , (C _6-10 )aryl or nitro.

In one embodiment, the degree of hydroxyl substitution ranges from about 0.5 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.1 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.2 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.3 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.4 to about 2.6.

In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 5,000 Da to about 250,000 Da. . In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 25,000 Da to about 250,000 Da. . In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 50,000 Da to about 250,000 Da. . In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. . In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. . In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da. .

In one embodiment of the regioselectively substituted cellulose ester, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl (aryl is unsubstituted substituted with 1 to 6 R ² groups), and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy , halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose ester, R ¹ is selected from (C _1-20 )alkyl. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose esters, R ¹ is (C _6-20 )aryl, where the aryl is unsubstituted or substituted with 1-6 R ² groups. and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 ) is selected from aryl or nitro; In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose esters, R ¹ is methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzo thiophenyl or heptadecanyl; In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M ^w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose ester, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.3. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose ester, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.1. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose ester, the degree of substitution of R ¹ -CO- at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.08. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose ester, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.06. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the composition of matter, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.04. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselectively substituted cellulose ester, R ¹ is (C _1-20 )alkyl. In one embodiment of the regioselectively substituted cellulose ester, R ¹ is halo(C _1-20 )alkyl. In one embodiment of the regioselectively substituted cellulose ester, R ¹ is (C _2-20 )alkenyl. In one embodiment of the regioselectively substituted cellulose ester, R ¹ is (C _3-7 )cycloalkyl. In one embodiment of the regioselectively substituted cellulose esters, R ¹ is (C _6-20 )aryl, where the aryl is unsubstituted or substituted with 1-6 R ² groups. and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 ) is selected from aryl or nitro; In one embodiment of the regioselectively substituted cellulose esters, R ¹ is a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups), where R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy , halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment of the regioselectively substituted cellulose ester, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _6-20 ) aryl (aryl is unsubstituted or substituted with 1-6 R ² groups) or 5-20 membered containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen selected from heteroaryl (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups);

In one embodiment of the regioselectively substituted cellulose ester, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl (aryl is unsubstituted substituted with 1 to 6 R ² groups), wherein R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, selected from halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment of the regioselectively substituted cellulose esters, R ¹ is methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzo thiophenyl or heptadecanyl;

In one embodiment of the regioselectively substituted cellulose ester, the regioselectively substituted cellulose ester further comprises a plurality of R ^-CO- substituents, wherein the R ^-CO- The degree of substitution (“C6DS _R4 ”) ranges from about 0.1 to about 1.0 and R ⁴ is (C _1-20 )alkyl, halo(C _1-5 )alkyl, (C _2-20 ) from alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1 to 6 R ⁵ groups), or from oxygen, sulfur and nitrogen selected from monocyclic or bicyclic heteroaryl (heteroaryl is unsubstituted or substituted with 1 to 6 R ⁶ groups) containing 1 to 3 independently selected heteroatoms; , R ⁵ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, ( C _6-10 )aryl or nitro, and R ⁶ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo , (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.5, wherein R ⁴ at the C3 The degree of —CO— substitution (“C3DS _R4 ”) ranges from about 0 to about 0.5. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In a class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.4, wherein R ⁴ — at the C3 position The degree of substitution of CO— (“C3DS _R4 ”) ranges from about 0 to about 0.4. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In a class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.3, wherein R ⁴ — at the C3 position The degree of substitution of CO— (“C3DS _R4 ”) ranges from about 0 to about 0.3. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In a class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.2, wherein R ⁴ — at the C3 position The degree of substitution of CO— (“C3DS _R4 ”) ranges from about 0 to about 0.2. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In one class of this embodiment, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da.

In one class of this embodiment, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da.

In one class of this embodiment, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In one class of this embodiment, R ⁴ is (C _1-20 )alkyl. In one class of this embodiment, R ⁴ is halo(C _1-5 )alkyl.

In one class of this embodiment, R ⁴ is (C _2-20 )alkenyl.

In one class of this embodiment, R ⁴ is (C _3-7 )cycloalkyl.

In one class of this embodiment, R ⁴ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ⁵ groups) and R ⁵ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one class of this embodiment, R ⁴ is a monocyclic or bicyclic heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R ⁶ groups), where R ⁶ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one class of this embodiment, R ⁴ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, ^R4 is methyl. In a subclass of this class, ^R4 is ethyl. In a subclass of this class, ^R4 is propyl. In a subclass of this class, ^R4 is 1-ethyl-pentyl-. In a subclass of this class, ^R4 is phenyl. In a subclass of this class, ^R4 is 3,4,5-trimethoxyphenyl. In a subclass of this class, ^R4 is 2-naphthyl. In a subclass of this class, ^R4 is benzothiophenyl. In a subclass of this class, ^R4 is heptadecanyl.

In one embodiment, C6DS _R1-CO- is less than 0.1. In one embodiment, C6DS _R1-CO- is less than 0.08. In one embodiment, C6DS _R1-CO- is less than 0.06. In one embodiment, C6DS _R1-CO- is less than 0.05. In one embodiment, C6DS _R1-CO- is less than 0.04. In one embodiment, C6DS _R1-CO- is less than 0.02.

In one embodiment, R ¹ -CO- is selected from acetyl, propionyl, butanoyl, benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl or benzothiophenyl-CO-. be

In one embodiment, R ¹ -CO- is propionyl. In one class of this embodiment, the degree of substitution of propionyl (ie, R ¹ —CO— is propionyl) is from about 1.0 to about 1.4, and the degree of substitution of propionyl at the C2 position (“C2DS _Pr ” ) is from 0.6 to 0.9 and the degree of substitution of propionyl at the C3 position (“C3DS _Pr ”) is from about 0.3 to about 0.5. In a subclass of this class, the degree of substitution of propionyl at the C6 position (“C6DS _Pr ”) is less than 0.05.

In one embodiment, R ¹ -CO- is a combination comprising benzoyl and naphthoyl. In one class of this embodiment, the degree of substitution for benzoyl is from about 0.2 to about 1.2 and the degree of substitution for naphthoyl is from about 0.8 to about 1.8.

In one class of this embodiment, the degree of substitution for benzoyl is from about 0.4 to about 0.8, the degree of substitution for naphthoyl is from about 1.2 to about 1.6, and the combination of benzoyl and naphthoyl C6 The degree of substitution at the positions is less than 0.05.

In one embodiment, R ¹ -CO- is a combination comprising propionyl and (C _6-20 )aryl. In one class of this embodiment, the combination of propionyl and (C _6-20 )aryl has a degree of substitution at the C6 position of less than 0.1.

In one embodiment, R ¹ -CO- is a combination comprising propionyl and benzoyl. In one class of this embodiment, the degree of substitution for propionyl is from about 0.4 to about 0.7, the degree of substitution for benzoyl is from about 0.2 to about 0.5, and the combined C6 The degree of substitution at the positions is less than 0.05.

In one class of this embodiment, the degree of substitution for propionyl is from about 1.1 to about 1.8, the degree of substitution for benzoyl is from about 0.1 to about 0.5, and the combined C6 The degree of substitution at the positions is less than 0.05.

In one embodiment, R ¹ -CO- is a combination comprising propionyl and naphthoyl. In one class of this embodiment, the degree of substitution for propionyl ranges from 0.2 to 0.9 and the degree of substitution for naphthoyl ranges from 0.4 to 1.4.

In one embodiment, R ¹ -CO- is propionyl or a combination containing 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen. In one class of this embodiment, the degree of substitution for propionyl ranges from 0.2 to 0.4 and the degree of substitution for naphthoyl ranges from 0.9 to 1.1.

In one embodiment, R ₁ -CO- is a combination comprising propionyl and (C _6-20 )alkyl-CO-.

In one embodiment, R ¹ -CO- is a combination comprising acetyl and (C _6-20 )aryl-CO-. In a class of this embodiment, the degree of substitution for acetyl is from about 0.7 to about 0.9 and the degree of substitution for (C _6-20 )aryl-CO- is from about 0.1 to about 0.5. and the degree of substitution at the C6 position of the combination of acetyl and (C _6-20 )aryl-CO- is less than 0.1.

In one embodiment, R ¹ -CO- is a combination comprising acetyl and a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen. In one class of this embodiment, 5- to 20-membered acetyl having a degree of substitution of from about 0.8 to about 1.1 and containing 1-3 heteroatoms independently selected from oxygen, sulfur, and nitrogen. The degree of substitution for heteroaryl is from about 0.1 to about 0.3 and the degree of substitution at the C6 position for the combination of acetyl and benzoyl is less than 0.1.

The present application also discloses regioselectively substituted cellulose esters comprising: (i) multiple R ¹ -CO-substituents, (ii) multiple R ⁴ -CO-substituents, (iii) Multiple hydroxyl substituents, where the degree of substitution of R ¹ —CO— at the C2 position (“C2DS _R1 ”) ranges from about 0.2 to about 1.0, and R ¹ — at the C3 position The degree of substitution of CO— (“C3DS _R1 ”) is in the range of about 0.2 to about 1.0, and the degree of substitution of R ¹ —CO— at the C6 position (“C6DS _R1 ”) is in the range of about 0 to about 0. .5, the degree of substitution of R ⁴ —CO— at the C6 position (“C6DS _R4 ”) ranges from about 0.1 to about 1.0, and the degree of substitution of hydroxyl ranges from about 0 to about 2. .6 and R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 ) aryl (aryl is unsubstituted or substituted with 1-6 R ² groups) or 5-20 containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen is selected from membered heteroaryl (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups), R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl; , (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro, and R ³ is (C _1-6 ) alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro is selected and R ⁴ is (C _1-20 )alkyl, halo(C _1-5 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1 to 6 R ⁵ groups), or monocyclic or bicyclic containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen heteroaryl (heteroaryl is unsubstituted or substituted with 1 to 6 R ⁶ groups), R ⁵ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro, R ⁶ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, selected from halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment, the degree of hydroxyl substitution ranges from about 0.5 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.1 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.2 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.3 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.4 to about 2.6.

In one embodiment R ¹ -CO- is selected from acetyl, propionyl, butanoyl, benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl- or benzothiphene-CO- , R ⁴ -CO- is selected from acetyl, propionyl, butyryl, benzoyl, acetyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl- or benzothiphene-CO-.

In one embodiment, C6DS _R1-CO- is less than 0.1. In one embodiment, C6DS _R1-CO- is less than 0.08. In one embodiment, C6DS _R1-CO- is less than 0.06. In one embodiment, C6DS _R1-CO- is less than 0.05. In one embodiment, C6DS _R1-CO- is less than 0.04. In one embodiment, C6DS _R1-CO- is less than 0.02.

In one embodiment, R ¹ -CO- is propionyl.

In a class of this embodiment, R ⁴ --CO-- is (C _6-20 )aryl-CO--.

In one class of this embodiment, R ⁴ --CO-- is a combination of pivaloyl and (C _6-20 )aryl-CO--. In a subclass of this class, (C _6-20 )aryl-CO- is selected from benzoyl and naphthoyl. In a subsubclass of this subclass, the degree of substitution of pivaloyl is from 0.6 to 0.9. The degree of substitution of (C _6-20 )aryl-CO- is from 0.2 to 0.5.

In one class of this embodiment, the degree of substitution of propionyl is from about 1.0 to about 1.4, the degree of substitution of propionyl at C2 is from 0.6 to 0.9, and the degree of substitution of propionyl at C3 is from about 1.0 to about 1.4. The degree of substitution is from about 0.3 to about 0.5.

In a subclass of this class, the degree of substitution of propionyl at the C6 position is less than 0.05. In a subsubclass of this subclass, the degree of substitution for pivaloyl is from 0.6 to 0.9 and the degree of substitution for (C _6-20 )aryl-CO- is from 0.2 to 0.5.

In a subclass of this class, R ⁴ --CO-- is (C _6-20 )aryl-CO--.

In a subclass of this class, R ⁴ -CO- is a combination of pivaloyl and (C _6-20 )aryl-CO-. In a subsubclass of this subclass, (C _6-20 )aryl-CO- is selected from benzoyl and naphthoyl. In a subsubsubclass of this subsubclass, the degree of substitution for pivaloyl is from 0.6 to 0.9 and the degree of substitution for (C _6-20 )aryl-CO- is from 0.2 to 0.5. In one subsubsubclass of this subsubsubclass, the degree of substitution of propionyl at the C6 position is less than 0.05. In a subsubsubsubclass of this subsubsubclass, the degree of substitution for pivaloyl is from 0.6 to 0.9 and the degree of substitution for (C _6-20 )aryl-CO- is from 0.2 to 0.5.

In one embodiment, R ¹ -CO- is a combination comprising benzoyl and naphthoyl.

In a class of this embodiment, R ⁴ -CO- is (C _1-6 )alkyl-CO-.

In a subclass of this class, the degree of substitution for benzoyl is from about 0.2 to about 1.2, the degree of substitution for naphthoyl is from about 0.8 to about 1.8, and (C _1-6 )alkyl- The degree of substitution of CO- is less than 0.5.

In a subsubclass of this subclass, R ⁴ --CO-- is propionyl.

In one embodiment, R ¹ -CO- is a combination of propionyl and benzoyl.

In one class of this embodiment, R ⁴ --CO-- is a combination of propionyl and benzoyl.

In a subclass of this class, the total degree of substitution of benzoyl at the C2 and C3 combined positions is from 0.1 to 0.6 and the degree of substitution of propionyl at the combined positions of C2 and C3 is from 0.5 to 1.4, the degree of substitution for benzoyl at the C6 position is 0-0.8, and the degree of substitution for propionyl is 0-1.0.

In a subsubclass of this subclass, the degree of substitution of benzoyl at C6 is from 0.1 to 0.2 and the degree of substitution of propionyl at C6 is from 0.4 to 0.8.

In a subclass of this class, the total degree of substitution of benzoyl at the C2 and C3 combined positions is from 0.05 to 2.0 and the degree of substitution of propionyl at the combined positions of C2 and C3 is from 0.5 to 1.4, the degree of substitution for benzoyl at the C6 position is 0-0.8, and the degree of substitution for propionyl is 0-1.0.

In a subsubclass of this subclass, the degree of substitution of benzoyl at C6 is from 0.1 to 0.2 and the degree of substitution of propionyl at C6 is from 0.4 to 0.8.

In a subclass of this class, the total degree of substitution of benzoyl at the C2 and C3 combined positions is from 0.6 to 2.0 and the degree of substitution of propionyl at the combined positions of C2 and C3 is from 0.5 to 1.4, the degree of substitution for benzoyl at the C6 position is 0-0.8, and the degree of substitution for propionyl is 0-1.0.

In a subsubclass of this subclass, the degree of substitution of benzoyl at C6 is from 0.1 to 0.2 and the degree of substitution of propionyl at C6 is from 0.4 to 0.8.

The present application also discloses regioselectively substituted trifluoroacetylcellulose esters including:
(i) multiple trifluoroacetyl substituents;
wherein the degree of substitution at the C2 position (“C2DS _TFA ”) is from about 0 to about 0.1;
wherein the degree of substitution at the C3 position (“C3DS _TFA ”) is from about 0 to about 0.1;
wherein the degree of substitution at the C6 position (“C6DS _TFA ”) is from about 0.9 to about 1.0;
Here, the regioselectively substituted trifluoroacetylcellulose esters have weight average molecular weights (“M _w ”) ranging from about 50,000 Da to about 600,000 Da.

In one class of embodiments, the C2DS _TFA is from about 0 to about 0.05 and the C3DS _TFA is from about 0 to about 0.05. In one class of embodiments, the C2DS _TFA is from about 0 to about 0.02 and the C3DS _TFA is from about 0 to about 0.02. In one class of embodiments, the C2DS _TFA is from about 0 to about 0.01 and the C3DS _TFA is from about 0 to about 0.02.

In one class of this embodiment, the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) ranging from about 50,000 Da to about 250,000 Da. In one class of this embodiment, the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) ranging from about 50,000 Da to about 150,000 Da.

Films The present application discloses films comprising cellulose esters comprising: (i) multiple R ¹ -CO-substituents, (ii) multiple R ⁴ -CO-substituents, (iii) multiple hydroxyl substitutions. group, where the degree of substitution of R ¹ -CO- at the C2 position (“C2DS _R1 ”) ranges from about 0.2 to about 1.0 and the degree of substitution of R ¹ -CO- at the C3 position degree (“C3DS _R1 ”) ranges from about 0.2 to about 1.0, and the degree of substitution of R ¹ —CO— at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.5. wherein the degree of substitution of R ^-CO- at the C6 position ("C6DS _R4 ") ranges from about 0.1 to about 1.0 and the degree of substitution of hydroxyl ranges from about 0 to about 2.6 and R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl is unsubstituted or substituted with 1-6 R ³ groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _{1 -6} ) alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro, and R ³ is (C _1-6 )alkyl, halo (C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro; ⁴ is (C _1-20 )alkyl, halo(C _1-5 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (where aryl is unsubstituted or substituted with 1 to 6 R ⁵ groups), or a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen (hetero aryl is unsubstituted or substituted with 1 to 6 R ⁶ groups) and R ⁵ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _{1- 6} ) alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, ( C _6-10 )aryl or nitro, and R ⁶ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo , (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment, the degree of hydroxyl substitution ranges from about 0.5 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.1 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.2 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.3 to about 2.6. In one embodiment, the degree of hydroxyl substitution ranges from about 0.4 to about 2.6.

In one embodiment of the regioselective cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 5,000 Da to about 250,000 Da. In one embodiment of the regioselective cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 25,000 Da to about 250,000 Da. In one embodiment of the regioselective cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 50,000 Da to about 250,000 Da. In one embodiment of the regioselective cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one embodiment of the regioselective cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one embodiment of the regioselective cellulose ester, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselective cellulose ester, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl (aryl is unsubstituted or 1 substituted with ~6 R ² ), where R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _{1- 6} ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro; In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselective cellulose ester, R ¹ is selected from (C _1-20 )alkyl. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselective cellulose ester, R ¹ is (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _{6- 10} ) selected from aryl or nitro; In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the regioselective cellulose ester, R ¹ is methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. selected from In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the film, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.3. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the film, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.1. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the film, the degree of substitution of R ¹ -CO- at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.08. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the film, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.06. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the film, the degree of substitution of R ¹ —CO—at the C6 position (“C6DS _R1 ”) ranges from about 0 to about 0.04. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In one class of this embodiment, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 and R ² is ( _{C 1-6} )alkyl, halo(C ^1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from (C _1-20 )alkyl. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one class of this embodiment, R ¹ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 80,000 Da to about 150,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) of the regioselectively substituted cellulose ester ranges from about 100,000 Da to about 150,000 Da.

In one embodiment of the film, R ¹ is (C _1-20 )alkyl. In one embodiment of the composition of matter, R ¹ is halo(C _1-20 )alkyl. In one embodiment of the composition, R ¹ is (C _2-20 )alkenyl. In one embodiment of the composition of matter, R ¹ is (C _3-7 )cycloalkyl. In one embodiment of the composition of matter, R ¹ is (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups) and R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _{6-10 )} ) aryl or nitro. In one embodiment of the composition of matter, R ¹ is a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (whether the heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups), where R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _{1 -6} ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment of the film, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R ³ groups).

In one embodiment of the film, R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl or (C _6-20 )aryl, where aryl is unsubstituted or 1-6 substituted with R ² groups), wherein R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy , halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment of the film, R ¹ is selected from methyl, ethyl, propyl, 1-ethylpentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl.

In one embodiment of the film, the regioselectively substituted cellulose ester further comprises a plurality of R ^-CO- substituents, and the degree of substitution of R ^-CO- at the C6 position ("C6DS _R4 ") ranges from about 0.1 to about 1.0 and R ⁴ is (C _1-20 )alkyl, halo(C _1-5 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cyclo alkyl, (C _6-20 )aryl (where aryl is unsubstituted or substituted with 1-6 R ⁵ groups), or 1-3 independently selected from oxygen, sulfur and nitrogen wherein R ⁵ is ⁽ C _1-6 ) alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro is selected and R ⁶ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl , (C _6-10 )aryl or nitro.

In one class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.5, wherein R ⁴ at the C3 The degree of —CO— substitution (“C3DS _R4 ”) ranges from about 0 to about 0.5. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In a class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.4, wherein R ⁴ — at the C3 position The degree of substitution of CO— (“C3DS _R4 ”) ranges from about 0 to about 0.4. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In a class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.3, wherein R ⁴ — at the C3 position The degree of substitution of CO— (“C3DS _R4 ”) ranges from about 0 to about 0.3. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In a class of this embodiment, the degree of substitution of R ⁴ —CO— at the C2 position (“C2DS _R4 ”) ranges from about 0 to about 0.2, wherein R ⁴ — at the C3 position The degree of substitution of CO— (“C3DS _R4 ”) ranges from about 0 to about 0.2. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da. In a subclass of this class, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In one class of this embodiment, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 250,000 Da.

In one class of this embodiment, the weight average molecular weight (“M _w ”) ranges from about 80,000 Da to about 100,000 Da.

In one class of this embodiment, the weight average molecular weight (“M _w ”) ranges from about 100,000 Da to about 250,000 Da.

In one class of this embodiment, R ⁴ is (C _1-20 )alkyl. In one class of this embodiment, R ⁴ is halo(C _1-5 )alkyl.

In one class of this embodiment, R ⁴ is (C _2-20 )alkenyl.

In one class of this embodiment, R ⁴ is (C _3-7 )cycloalkyl.

In one class of this embodiment, R ⁴ is (C _6-20 )aryl (wherein the aryl is unsubstituted or substituted with 1-6 R ⁵ groups) and R ⁵ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one class of this embodiment, R ⁴ is a monocyclic or bicyclic heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R ⁶ groups), where R ⁶ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one class of this embodiment, R ⁴ is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl. . In a subclass of this class, ^R4 is methyl. In a subclass of this class, ^R4 is ethyl. In a subclass of this class, ^R4 is propyl. In a subclass of this class, ^R4 is 1-ethyl-pentyl-. In a subclass of this class, ^R4 is phenyl. In a subclass of this class, ^R4 is 3,4,5-trimethoxyphenyl. In a subclass of this class, ^R4 is 2-naphthyl. In a subclass of this class, ^R4 is benzothiophenyl. In a subclass of this class, ^R4 is heptadecanyl.

In one embodiment of the film, the film is a uniaxial or biaxial optical film. In one class of this embodiment, the film is a uniaxial optical film. In one class of this embodiment, the film is a biaxial optical film.

In one embodiment, the film has a birefringence (“Δn”) of about 0.007 to about 0.010 when measured at a wavelength of 589 nm. In one embodiment, the film has a Δn of about 0.008 to about 0.010 when measured at a wavelength of 589 nm. In one embodiment, the film has a Δn of about 0.009 to about 0.010 when measured at a wavelength of 589 nm.

In one embodiment, the film has a % haze of less than about 0.9. In one embodiment, the film has a % haze of less than about 0.8. In one embodiment, the film has a % haze of less than about 0.7. In one embodiment, the film has a % haze of less than about 0.6. In one embodiment, the film has a % haze of less than about 0.5. In one embodiment, the film has a % haze of less than 0.4. In one embodiment, the film has a % haze of less than about 0.3. In one embodiment, the film has a % haze of less than about 0.2.

In one embodiment, the film is a C+ film, C- film, A+ film or A- film. In one class of this embodiment, the film is a C+ film. In one class of this embodiment, the film is a C-film. In one class of this embodiment, the film is an A+ film. In one class of this embodiment, the film is an A-film. In one class of this embodiment, the film is an A-film.

In one embodiment, the film is a C+ film, C- film, reverse A film or NRZ film.

In one class of this embodiment are C+ films. In a subclass of this class, the films have an out-of-plane retardation (“R _th ”) as measured at 589 nm divided by film thickness (“d”) in the range of 0 to 20. In a subsubclass of this subclass, the film is uniaxially, biaxially or 45 degree oriented.

In one class of this embodiment, the film is a C-film. In a subclass of this class, the film has an out-of-plane retardation (“R _th ”) divided by film thickness (“d”) as measured at a wavelength of 589 nm in the range of 0 to about −12 It is in. In a subsubclass of this subclass, the film is uniaxially, biaxially or 45 degree oriented. In a subclass of this class, the film has an out-of-plane retardation (“R _th ”) divided by film thickness (“d”) as measured at a wavelength of 589 nm in the range of 0 to about −17 It is in. In a subsubclass of this subclass, the film is uniaxially, biaxially or 45 degree oriented. In a subclass of this class, the films have an out-of-plane retardation (“R _th ”) divided by film thickness (“d”) measured at a wavelength of 589 nm from −2 to about −17. in the range. In a subsubclass of this subclass, the film is uniaxially, biaxially or 45 degree oriented. In a subclass of this class, the films have an out-of-plane retardation (“R _th ”) divided by film thickness (“d”) measured at a wavelength of 589 nm from −5 to about −17. in the range. In a subsubclass of this subclass, the film is uniaxially, biaxially or 45 degree oriented.

In one class of this embodiment, the film is a reverse A film. In a subclass of this class, the films satisfy the relationships R _e 450/R _e 550<1 and R _e 650/R _e 550>1, where R _e 450, R _e 550 and R _e 650 are: In-plane retardation when measured at wavelengths of 450 nm, 550 nm and 650 nm, respectively. In a subsubclass of this subclass, the in-plane retardation (“R _e ”) of the film as measured at a wavelength of 589 nm ranges from about 100 nm to about 300 nm. In one subsubclass of this subsubclass, the film is uniaxially, biaxially or 45 degree oriented.

In one class of this embodiment, the film is an NRZ film. In a subclass of this class, the films satisfy the relationships R _e 450/R _e 550<1 and R _e 650/R _e 550>1, where R _e 450, R _e 550 and R _e 650 are: In-plane retardation as measured at wavelengths of 450 nm, 550 nm and 650 nm, respectively. In a subsubclass of this subclass, the in-plane retardation (“R _e ”) of the film as measured at a wavelength of 589 nm ranges from about 100 nm to about 300 nm. In one subsubclass of this subsubclass, the out-of-plane retardation (“R _e ”) of the film as measured at a wavelength of 589 nm ranges from about 0 nm to about −50 nm. In one subsubsubclass of this subsubsubclass, the film is uniaxially, biaxially or 45 degree stretched.

In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of −50 to 50, as measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the film thickness (“d”), measured at a wavelength of 589 nm, in the range of −50 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of 0 to 50, measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −20 to 20. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −20 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of 0 to 20, measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of −15 to 15, as measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −15 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of 0 to 15 as measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of −10 to 10 as measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −10 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of 0 to 10, as measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have R _th nm in the range of −5 to 0. In one embodiment, the films disclosed above have R _th nm in the range of −5 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of 0 to 5, as measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −3 to 3. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −3 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of 0 to 3, as measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of −1 to 1, measured at a wavelength of 589 nm. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −1 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film in the range of 0 to 1, measured at a wavelength of 589 nm. In one embodiment, the film disclosed above has an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −0.5 to 0.5. be. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of −0.5 to 0. In one embodiment, the films disclosed above have an R _th divided by the thickness (“d”) of the film, measured at a wavelength of 589 nm, in the range of 0 to 0.5.

Any of the above films can have a thickness ranging from about 40 to about 120 μm, from about 40 to about 70 μm, or from about 5 to about 20 μm. Thickness and average thickness are used interchangeably in this application. As used herein, "average thickness" shall represent the average of at least three equally spaced measurements of the thickness of the optical film.

In various embodiments, additives such as plasticizers, stabilizers, UV absorbers, anti-blocking agents, slip agents, lubricants, dyes, pigments, retardation modifiers are used in the preparation of the optical films described above. It may be mixed with optionally substituted cellulose esters. Examples of these additives can be found, for example, in U.S. Patent Application Publication Nos. 2009/0050842, 2009/0054638 and 2009/0096962, the contents of which are incorporated herein by reference. take in.

Any of the above optical films can be made by solvent casting, melt extrusion, lamination or coating processes. These procedures are generally known in the art. Examples of solvent casting, melt extrusion, lamination and coating processes can be found, for example, in U.S. Patent Application Publication Nos. 2009/0050842, 2009/0054638 and 2009/0096962, the contents of which are incorporated herein by reference. Further examples of solvent casting, melt extrusion, laminating and coating processes for forming films are found, for example, in US Pat. 2005/0133953 and 2010/0055356, the contents of which are incorporated herein by reference.

To help obtain desired Re _{and Rth} values using the regioselectively substituted cellulose esters described herein, the film can be stretched. Desired R _e and R _th can be achieved by adjusting stretching conditions such as stretching temperature, stretching type (uniaxial or biaxial), stretching ratio, preheating time and temperature, and post-stretching annealing time and temperature. The exact stretching conditions may depend on the particular composition of the regioselectively substituted cellulose ester, the amount and type of plasticizer, and the glass transition temperature of that particular composition. Therefore, the specific stretching conditions can vary greatly. In various embodiments, the stretching temperature can range from about 160°C to about 210°C. Additionally, the draw ratio based on 1.0 in the machine direction (“MD”) can range from about 1.3 to about 2.0 in the transverse direction (“TD”). The preheat time can range from about 10 to about 300 seconds and the preheat temperature can be the same as the draw temperature. Post-annealing times can range from about 0 to about 300 seconds, and post-annealing temperatures can range from about 10 to about 40° C. below the stretching temperature. The thickness of the film may depend on the thickness of the film before stretching and the stretching conditions. After stretching, the film thickness can be from about 1 μm to about 500 μm, from about 5 μm to about 200 μm, or from about 10 μm to about 120 μm.

In addition to optical properties, films prepared from the regioselectively substituted cellulose esters described herein possess other valuable characteristics. Many conventional cellulose esters used in LCD displays have relatively high moisture absorption, affecting dimensional stability and changing the optical values of the films. Films prepared from the regioselectively substituted cellulose esters described herein have low moisture absorption and the optical values of the films change little at high humidity and temperature. Thus, in various embodiments, the regioselectively substituted cellulose ester can contain less than 2 wt% moisture, less than 1 wt% moisture, or less than 0.5 wt% moisture. In various other embodiments, the change in _Re of the cellulose ester film is less than 4%, less than 1%, or less than 0.5% when stored at 60°C and 100% relative humidity for 240 hours. can.

The regioselectively substituted cellulose esters described herein are surprisingly thermally stable, making them very useful for melt extrusion of films. Accordingly, one aspect of the present invention relates to regioselectively substituted cellulose esters having a weight loss of less than 10% by thermogravimetric analysis at 330°C, 340°C or 350°C.

As noted above, the optical films described herein can be used in LCDs. In particular, the optical films described above can be used as part or all of the compensation films of the polarizer stacks of LCDs. As mentioned above, a polarizer stack typically includes two crossed polarizers positioned on opposite sides of a liquid crystal layer. A compensation film can be placed between the liquid crystal layer and one of the polarizers. In one or more embodiments, the single-layer optical films described above can themselves be used as compensation films (ie, waveplates) in LCDs. In such embodiments, a single layer optical film can be placed between the liquid crystal layer of the LCD and one of the polarizing filters. In other embodiments, the -A optical films described above can be used in LCD compensation films (ie, wave plates). In such embodiments, the -A optical film can be positioned adjacent to at least one additional optical film, and such additional optical film can be a -C optical film. In yet another embodiment, the +C optical films described above can be used in LCD compensation films (ie, waveplates). In such embodiments, the +C optical film can be positioned adjacent to at least one additional optical film, and such additional optical film can be a +A optical film. In any of the above embodiments, LCDs prepared with the optical films described herein can operate in an in-plane switching (“IPS”) mode.

The optical compensation films described herein can also be used in OLEDs. For example, a QWP is combined with a linear polarizer to form a circular polarizer. Placing a circular polarizer in front of the OLED device reduces the ambient light reflected from the OLED metal electrodes to improve display quality, such as high contrast ratio and low color shift, especially when the QWP has near-ideal inverse dispersion. can be improved.

The optical films described herein can also be used in circular polarizers. In particular, quarter-wave plates can be prepared that include one or more of the above-described optical films of the present invention that can be used to convert linearly polarized light to circularly polarized light. This aspect can be of particular value for use with circularly polarized three-dimensional (“3D”) glasses and/or 3D media displays, such as televisions (“3D TV”). Accordingly, in one or more embodiments, quarter wave plates can be prepared that include the single layer optical films described above. In various other embodiments, quarter-wave plates can be prepared that include the -A optical films described above. Such quarter-wave plates can be applied to the glass of 3-D TVs, such as on top of polarizing stacks. Moreover, such a quarter-wave plate can be applied to the glass of 3D glasses. In the case of 3-D glasses, the optical films can be applied such that the optical axis of one lens is perpendicular or substantially perpendicular to the optical axis of the other lens. As a result of 3-D glasses, certain observed polarized light is blocked by one lens, but passes through the other lens, leading to the observed 3D optical effect. In various embodiments, quarter-wave plates comprising one or more of the optical films described above can be used with at least one additional polarizer, which can be a linear polarizer.

Any of the disclosed films can be incorporated into multilayer films. This application also relates to multilayer films comprising any of the disclosed films of this application.

METHODS This application describes the combined degree of substitution of C2 and C3 (“(C2+C3)DS)” ranging from about 0 to about 2.0 and the degree of substitution of C6 (“C6DS”) ranging from about 0 to about 0.6. A method for preparing a regioselectively substituted cellulose ester having a degree of
(1) In a reaction medium in a suitable solvent, cellulose is combined with about 1.4 equivalents to about 1.8 equivalents of trifluoroacetic anhydride (“TFAA”) and about 0.1 equivalents to about 0.8 equivalents of contacting with one or more first carboxylic acids;
wherein the equivalent weights of TFAA and first carboxylic acid are based on the sum of cellulose anhydride glucosyl units,
Disclose how.

Suitable solvents for this process are any solvents capable of dissolving or partially dissolving the starting cellulose or the cellulose esters formed during the reaction leading to the desired product. In one embodiment of this method, a suitable solvent is trifluoroacetic acid.

The acyl substituents contributing to (C2+C3)DS and C6DS are acyl substituents derived from the first carboxylic acid or any acylating compound.

In one embodiment of this method, C6DS is less than 0.4. In one embodiment of this method, C6DS is less than 0.2. In one embodiment of this method, C6DS is less than 0.1. In one embodiment of this method, C6DS is less than 0.08. In one embodiment of this method, C6DS is less than 0.06. In one embodiment of this method, C6DS is less than 0.04. In one embodiment of this method, C6DS is less than 0.02.

In one embodiment of this method, further comprising (2) adding 0.1 to 2.0 equivalents of one or more acyl donors, wherein the equivalents of acyl donor is the total anhydroglucosyl units of cellulose based on. In one class of this embodiment, the acyl donor is selected from a second carboxylic acid or anhydride. In a subclass of this class, the acyl donor is the second carboxylic acid. In a subclass of this class, the acyl donor is an anhydride.

In one class of this embodiment, the acyl donor is added after at least 50% of the first carboxylic acid is consumed. In a subclass of this class, the acyl donor is selected from a second carboxylic acid or anhydride. In a subsubclass of this subclass, the acyl donor is the second carboxylic acid. In a subsubclass of this subclass, the acyl donor is an anhydride.

In one class of this embodiment, the acyl donor is added after at least 80% of the first carboxylic acid is consumed. In a subclass of this class, the acyl donor is selected from a second carboxylic acid or anhydride. In a subsubclass of this subclass, the acyl donor is the second carboxylic acid. In a subsubclass of this subclass, the acyl donor is an anhydride.

In one class of this embodiment, the acyl donor is added after at least 90% of the first carboxylic acid is consumed. In a subclass of this class, the acyl donor is selected from a second carboxylic acid or anhydride. In a subsubclass of this subclass, the acyl donor is the second carboxylic acid. In a subsubclass of this subclass, the acyl donor is an anhydride.

In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) ranging from about 5,000 Da to about 250,000 Da. In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) ranging from about 25,000 Da to about 250,000 Da. In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) ranging from about 50,000 Da to about 250,000 Da. In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) ranging from about 80,000 Da to about 250,000 Da. In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) ranging from about 100,000 Da to about 250,000 Da.

In one embodiment of this method, the first carboxylic acid is R ¹ -COOH;

wherein R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl , (C _6-10 )aryl or nitro, and wherein R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) selected from alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment of this method, the second carboxylic acid is R ¹ -COOH;

wherein R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo alkyl, (C _6-10 )aryl or nitro, and wherein R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo( C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment of this method, the cellulose is softwood cellulose, hardwood cellulose, cotton linter cellulose or microcrystalline cellulose. In one embodiment of this method, the cellulose is Placetate F cellulose.

In one embodiment of this method, the reaction medium is set to a temperature in the range of about 20°C to about 80°C. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 35°C to about 75°C. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 0.degree. C. to about 20.degree. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 30°C to about 50°C. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 50°C to about 80°C.

The present application provides C2 degree of substitution (“C2DS”) from 0.01 to 1, C3 degree of substitution (“C3DS”) from 0.01 to 1 and C6 degree of substitution (“C6DS”) from about 0 to about 0.1 A method for preparing a regioselectively substituted cellulose ester having
(1) In a reaction medium containing a suitable solvent, cellulose is combined with about 0.5 to about 5.0 equivalents of trifluoroacetic anhydride (“TFAA”) and 0.1 to 2.0 equivalents of one or more secondary contacting with an acylating agent (“FAA”) to esterify at least a portion of the cellulose, thereby producing a regioselectively substituted cellulose ester;
A method is disclosed herein wherein the equivalent weights of TFAA and FAA are based on the total anhydroglucosyl units of the cellulose.

The acyl substituents contributing to (C2+C3)DS and C6DS are acyl substituents derived from FAA or any other acylating compound added to the reaction medium.

Suitable solvents for this process are any solvents capable of dissolving or partially dissolving the starting cellulose or the cellulose esters produced during the reaction leading to the desired product. In one embodiment of this method, a suitable solvent is trifluoroacetic acid.

In one embodiment of this method, C6DS is less than 0.4. In one embodiment of this method, C6DS is less than 0.2. In one embodiment of this method, C6DS is less than 0.1. In one embodiment of this method, C6DS is less than 0.08. In one embodiment of this method, C6DS is less than 0.06. In one embodiment of this method, C6DS is less than 0.04. In one embodiment of this method, C6DS is less than 0.02.

In one embodiment of this method, TFAA is present from 0.5 equivalents to about 5.0 equivalents. In one embodiment of this method, TFAA is present from 0.5 equivalents to about 3.0 equivalents. In one embodiment of this method, TFAA is present at 0.5 equivalents to about 2.0 equivalents. In one embodiment of this method, TFAA is present from 1.0 equivalents to about 2.0 equivalents.

In one embodiment of this method, one or more FAAs are introduced after the introduction of TFAA. In one class of this embodiment, one or more of FAA and TFAA are added while dissolved in a suitable solvent. In a subclass of this class, the suitable solvent is trifluoroacetic acid. In one embodiment of this method, one or more FAAs are introduced prior to the introduction of TFAA. In one class of this embodiment, one or more of FAA and TFAA are added while dissolved in a suitable solvent. In a subclass of this class, the suitable solvent is trifluoroacetic acid. In one embodiment of this method, one or more of FAA and TFAA are introduced simultaneously. In one class of this embodiment, one or more of FAA and TFAA are added while dissolved in a suitable solvent. In a subclass of this class, the suitable solvent is trifluoroacetic acid.

In one embodiment of this method, FAA is selected from acid anhydrides or acid halides. In one embodiment of this method, the FAA is selected from symmetrical anhydrides or mixed anhydrides. In one class of this embodiment, the mixed anhydride is produced in the reaction medium by the addition of the carboxylic acid. In one embodiment of this method, FAA is an acid halide.

In one embodiment, FAA is R ^1a -C(O)OC(O)-R ^1b ;
wherein R ^1a and R ^1b are independently (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _{6- 20} ) aryl (aryl is unsubstituted or substituted with 1 to 6 R ² groups) or contains 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen 5 -20 membered heteroaryl (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups);
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo alkyl, (C _6-10 )aryl or nitro, and wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo (C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

In one embodiment, FAA is R ^1a -C(O)X;
wherein R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo selected from alkyl, (C _6-10 )aryl or nitro;
wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 ) is selected from cycloalkyl, (C _6-10 )aryl or nitro, and X is chloro, bromo or iodo.

In one embodiment of this method, the cellulose is hardwood cellulose, softwood cellulose, cotton linter cellulose or microcrystalline cellulose. In one embodiment of this method, the cellulose is Placetate F cellulose.

In one embodiment of this method, the reaction medium is set to a temperature in the range of about 20°C to about 80°C. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 35°C to about 75°C. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 0.degree. C. to about 20.degree. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 30°C to about 50°C. In one class of this embodiment, the reaction medium is set to a temperature in the range of about 50°C to about 80°C.

The present application provides a method for preparing regioselectively substituted cellulose esters comprising:
(1) Cellulose in a first reaction medium comprising a first suitable solvent, 0.5-5.0 equivalents of trifluoroacetic anhydride (“TFAA”) and 0.1-2.0 equivalents of contacting with one or more first acylating agents (“FAA”) to esterify at least a portion of the cellulose, thereby providing a degree of C2 substitution of 0.01-1 (“C2DS”), 0.01-1 producing an intermediate regioselectively substituted cellulose ester having a degree of C3 substitution (“C3DS”) of 1 and a degree of C6 substitution (“C6DS”) of 0 to about 0.1;
where the equivalents of TFAA and FAA are based on the total anhydroglucosyl units of cellulose,
(2) isolating the regioselectively substituted cellulose ester (“IRSCE”) of said intermediate; and
(3) dissolving the intermediate regioselectively substituted cellulose ester in a second reaction medium comprising a second suitable solvent from 0.1 to 2.0 equivalents of one or more second contacting with an acylating agent (“SAA”);
A method is disclosed herein wherein the equivalent weight of SAA is based on the sum of the anhydroglucosyl units of the IRSCE.

The acyl substituents contributing to (C2+C3)DS and C6DS are acyl substituents derived from FAA or any acylating compound added to the first reaction medium.

A first suitable solvent for this process is any solvent capable of dissolving or partially dissolving the starting cellulose or the cellulose ester produced during the reaction leading to the desired product. In one embodiment of this method, the first suitable solvent is trifluoroacetic acid.

A second suitable solvent for this process is any solvent capable of dissolving or partially dissolving the starting cellulose or cellulose esters produced during the reaction and which is inert to the reaction. In one embodiment of this method, the second suitable solvent is methyl ethyl ketone, tetrahydrofuran, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide, dioxane, dimethylformamide, ethyl acetate, butyl acetate, selected from trichloromethane, pyridine or dichloromethane;

In one embodiment of this method, the first suitable solvent is trifluoroacetic acid and the second suitable solvent is methyl ethyl ketone, tetrahydrofuran, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide. , dioxane, dimethylformamide, ethyl acetate, butyl acetate, trichloromethane, pyridine or dichloromethane.

In one embodiment of this method, C6DS is less than 0.08. In one embodiment of this method, C6DS is less than 0.06. In one embodiment of this method, C6DS is less than 0.04. In one embodiment of this method, C6DS is less than 0.02.

In one embodiment of this method, TFAA is present from 0.5 equivalents to about 8.0 equivalents. In one embodiment of this method, TFAA is present from 0.5 equivalents to about 6.0 equivalents. In one embodiment of this method, TFAA is present from 0.5 equivalents to about 4.0 equivalents. In one embodiment of this method, TFAA is present from 0.5 equivalents to about 3.0 equivalents. In one embodiment, TFAA is present at 0.5 equivalents to about 2.0 equivalents. In one embodiment of this method, TFAA is present from 1.0 equivalents to about 2.0 equivalents.

In one embodiment of this method, one or more FAAs are introduced after introducing TFAA in TFA. In one embodiment of this method, one or more FAAs are introduced prior to introducing the TFAA in the TFA. In one embodiment of this method, one or more of FAA and TFAA in TFA are introduced simultaneously.

In one embodiment of this method, the FAA is selected from symmetrical anhydrides or mixed anhydrides. In one embodiment of this method, FAA is an acid halide.

In one embodiment of this method, the cellulose is hardwood cellulose, softwood cellulose, cotton linter cellulose or microcrystalline cellulose. In one embodiment of this method, the cellulose is Placetate F cellulose.

In one embodiment of this method, the first reaction medium is set at a temperature in the range of about 20°C to about 80°C. In one class of this embodiment, the first reaction medium is set to a temperature in the range of about 35°C to about 75°C. In one class of this embodiment, the first reaction medium is set to a temperature in the range of about 0.degree. C. to about 20.degree. In one class of this embodiment, the first reaction medium is set to a temperature in the range of about 30°C to about 50°C. In one class of this embodiment, the first reaction medium is set to a temperature in the range of about 50°C to about 80°C.

In one embodiment of this method, the second reaction medium is set at a temperature in the range of about 20°C to about 80°C. In one class of this embodiment, the second reaction medium is set at a temperature in the range of about 35°C to about 75°C. In one class of this embodiment, the second reaction medium is set to a temperature in the range of about 0.degree. C. to about 20.degree. In one class of this embodiment, the second reaction medium is set at a temperature in the range of about 30°C to about 50°C. In one class of this embodiment, the second reaction medium is set to a temperature in the range of about 50°C to about 80°C.

Embodiment Embodiment 1.
Regioselections with combined degrees of substitution at C2 and C3 (“(C2+C3)DS)” ranging from about 0 to about 2.0 and degrees of substitution at C6 (“C6DS”) ranging from about 0 to about 0.6 A method for preparing a functionally substituted cellulose ester comprising:
(1) In a reaction medium containing a suitable solvent, cellulose is combined with about 1.4 equivalents to about 1.8 equivalents of trifluoroacetic anhydride (“TFAA”) and about 0.1 equivalents to about 0.8 equivalents of contacting with one or more first carboxylic acids;
where the equivalents of TFAA and first carboxylic acid are based on the sum of cellulose anhydride glucosyl units,
Method.

Embodiment 2.
the first carboxylic acid is R ¹ -COOH;
wherein R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R ² groups), or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl , (C _6-10 )aryl or nitro, and wherein R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 ) alkoxy, halo, ( _C3-7 ) cycloalkyl, ( _C6-10 ) aryl or nitro.

Embodiment 3.
The method of any one of embodiments 1-2, wherein the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) in the range of about 50,000 Da to about 500,000 Da.

Embodiment 4.
The method of any one of embodiments 1-3, wherein the suitable solvent is trifluoroacetic acid.

Embodiment 5.
Regioselections with C2 degree of substitution (“C2DS”) from 0.01 to 1, C3 degree of substitution (“C3DS”) from 0.01 to 1 and C6 degree of substitution (“C6DS”) from about 0 to about 0.1 1. A method of preparing a functionally substituted cellulose ester comprising:
(1) In a reaction medium containing a suitable solvent, cellulose is combined with about 0.5 to about 5.0 equivalents of trifluoroacetic anhydride (“TFAA”) and 0.1 to 2.0 equivalents of one or more secondary contacting with an acylating agent (“FAA”) to esterify at least a portion of the cellulose, thereby producing a regioselectively substituted cellulose ester;
A method wherein the equivalents of TFAA and FAA are based on the total anhydroglucosyl units of the cellulose.

Embodiment 6.
6. The method of embodiment 5, wherein FAA is selected from acid anhydrides or acid halides.

Embodiment 7.
9. The method of embodiment 8, wherein FAA is an acid anhydride.

Embodiment 8.
10. The method of embodiment 9, wherein the acid anhydride is produced in the reaction medium by the addition of the carboxylic acid.

Embodiment 9.
FAA is R ^1a -C(O)OC(O)-R ^1b ;
wherein R ^1a and R ^1b are independently (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _{6- 20} ) aryl (aryl is unsubstituted or substituted with 1 to 6 R ² groups) or contains 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen 5 -20 membered heteroaryl (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups);
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo alkyl, (C _6-10 )aryl or nitro, and wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo 9. The method of any one of embodiments 5-8, wherein is selected from (C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl, (C _6-10 )aryl or nitro.

Embodiment 10.
A method for preparing a regioselectively substituted cellulose ester comprising:
(1) Cellulose in a first reaction medium comprising a first suitable solvent, 0.5-5.0 equivalents of trifluoroacetic anhydride (“TFAA”) and 0.1-2.0 equivalents of contacting with one or more first acylating agents (“FAA”) to esterify at least a portion of the cellulose, thereby providing a degree of C2 substitution of 0.01-1 (“C2DS”), 0.01-1 producing an intermediate regioselectively substituted cellulose ester having a degree of C3 substitution (“C3DS”) of 1 and a degree of C6 substitution (“C6DS”) of 0 to about 0.1;
where the equivalents of TFAA and FAA are based on the total anhydroglucosyl units of cellulose,
(2) isolating the regioselectively substituted cellulose ester (“IRSCE”) of said intermediate; and
(3) dissolving the intermediate regioselectively substituted cellulose ester in a second reaction medium comprising a second suitable solvent from 0.1 to 2.0 equivalents of one or more second contacting with an acylating agent (“SAA”);
A method wherein the equivalent weight of SAA is based on the sum of the anhydroglucosyl units of the IRSCE.

Embodiment 11.
A first suitable solvent is trifluoroacetic acid and a second suitable solvent is methyl ethyl ketone, tetrahydrofuran, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide, dioxane, dimethylformamide, ethyl acetate, 11. The method of embodiment 10, selected from butyl acetate, trichloromethane, pyridine or dichloromethane.

Embodiment 12.
11. The method of any one of embodiments 1, 5 or 10, wherein the cellulose is hardwood cellulose, softwood cellulose, cotton linter cellulose or microcrystalline cellulose.

Experimental Abbreviations AcOH is acetic acid, Ac ₂ O is acetic anhydride, AcCl is acetyl chloride, aq. is aqueous, Bu ₂ O is butanoic anhydride, BzOH is benzoic acid, Bz ₂ O is benzoic anhydride, Bzt is benzothiephenyl C—CO—, BztOH is benzothiephenyl- is COOH, BztCl is benzothiephenyl CO—Cl, °C is degrees Celsius, C2DS is the degree of substitution at the 2-position of the anhydroglucose residue, and C3DS is the degree of substitution at the 3-position of the anhydroglucose residue. where C6DS is the degree of substitution at the 6-position of the anhydroglucose residue, CIC is combustion ion chromatography, d is deuterated or deuterated, Da is Dalton, and DCE is dichloroethane. , DCM is dichloromethane, DEP is diethyl phthalate, DMAc is N,N-dimethylacetamide, DMAP is 4-dimethylaminopyridine, DMSO-d6 is hexadeuterated dimethylsulfoxide, min is minutes, equiv or eq. is equivalent weight, Et ₂ O is ethyl ether, Ex is example, g is gram, GPC is gel permeation chromatography, h is hour, Int is intermediate, KOAc is is potassium acetate, min is minutes, _Mw is weight average molecular weight, M is molarity, MEK is methyl ethyl ketone, MeOH is methanol, mg is milligrams, MHz is megahertz. , MIPK is methyl isopropyl ketone, mL or ml is milliliter, μL is microliter, mm is millimeter, mmHg is millimeter mercury, _N2 is nitrogen, NMR is nuclear magnetic resonance , Np is naphthyl, NpOH is 2-naphthoic acid, NpOH is 2-naphthoic acid, Np ₂ O is 2-naphthoic anhydride, ppm is parts per million, Pr is propionyl where iPrOH is isopropyl alcohol, PrOH is propionic acid, _Pr2O is propionic anhydride, RDS is the relative degree of substitution, rt is room temperature, SM is the starting material, TFA is is trifluoroacetic acid, TFAA is trifluoroacetic anhydride, Tg is the glass transition temperature, TMBz is 2,3,4-trimethoxybenzoyl, and TMBzOH is 2,3,4-trimethoxybenzoic acid. , TMBzCl is 2,3,5-trimethoxybenzoyl chloride, TPP is triphenyl phosphate, and wt % is weight percent.

Materials and Methods NMR Characterization NMR Characterization: Proton NMR data were acquired on a JEOL Model Eclipse-600 NMR spectrometer operating at 600 MHz. The sample tube size was 5 mm and the sample concentration was approximately 20 mg/mL DMSO- _d6 . Each spectrum was recorded at 80° C. using 64 scans and a pulse delay of 15 seconds. One to two drops of trifluoroacetic acid-d was added to each sample to shift residual water out of the spectral region of interest. Chemical shifts are reported in ppm from tetramethylsilane with the central peak of DMSO-d ₆ (2.49 ppm) as internal reference.

Quantitative ¹³ C NMR data were acquired on a JEOL Model GX-400 NMR spectrometer operating at 100 MHz. The sample tube size was 10 mm and the sample concentration was approximately 100 mg/mL DMSO- _d6 . Acetylacetonate chromium (III) was added to each sample at 5 mg/100 mg cellulose ester as a moderating agent. Each spectrum was typically recorded at 80° C. using 10000 scans and a 1 second pulse delay. Chemical shifts are reported in ppm from tetramethylsilane with the central peak of DMSO-d ₆ (39.5 ppm) as internal reference.

Proton and carbon NMR assignments, degrees of substitution and RDS of various acyl groups of cellulose esters were determined by adapting the procedure disclosed in US2012/0262650. C2, C3 and C6DS were determined by ¹³ C NMR. Total DS for any substituents is determined by ¹ H NMR.

Molecular Weight Determination For the cellulose esters described in this report, gel permeation chromatographic analysis was performed in N-methylpyrrolidinone containing 1% by weight glacial acetic acid. The instrument consisted of an Agilent series 1100 liquid chromatograph. The device components are a degasser, an isocratic pump set at a flow rate of 0.8 ml/min, an autosampler with an injection volume of 50 microliters, a column oven set at 40°C and a refractive index detector set at 40°C. included. The column set consisted of Agilent PLgel 10 micron guard (7.5 x 50 mm) and mixed B (7.5 x 300 mm) columns in series. Samples were prepared by weighing 25 mg into a 2-dram screw cap vial and dissolving in 10 ml of solvent. Ten microliters of toluene was added as a flow rate marker. The instrument was calibrated with a series of 14 narrow molecular weight polystyrene standards ranging in molecular weight from 580 to 3,750,000. Instrument control and data acquisition/processing were performed using Agilent GPC software version 1.2 build 3182.29519. For the cellulose samples described in this report, gel permeation chromatography analysis was performed with 70:30 N-methylpyrrolidinone/tributylmethylammonium dimethylphosphate on a weight basis. The instrument consisted of an Agilent series 1100 liquid chromatograph. The instrument components are a degasser, an isocratic pump with a flow rate set at 0.5 ml/min, an autosampler with an injection volume of 50 microliters, a column oven set at 60°C and a refractive index set at 40°C. Contains a detector. The column set consisted of Agilent PLgel 10 micron guard (7.5 x 50 mm) and mixed B (7.5 x 300 mm) columns in series. Samples were prepared by weighing 12.5 mg into a 2-dram screw cap vial and dissolving in 10 ml of solvent. 10 μL of toluene was added as a flow marker. The instrument was calibrated with a series of 14 narrow molecular weight polystyrene standards ranging in molecular weight from 580 to 3,750,000. Instrument control and data acquisition/processing were performed using Agilent GPC software version 1.2 build 3182.29519.

Dope preparation A solution of cellulose esters for film preparation and film manufacture was made by adapting the procedure disclosed in US 2012/0262650.

General procedure for film casting and optical film analysis. A dope was made optionally mixed with a plasticizer (10 wt%, DEP or TPP). A film is then cast onto glass using a knife applicator and dried for 10 minutes at room temperature for DCM-based dopes or at 85° C. for MEK and MIPK-based dope manufacturing dopes in a forced air oven. rice field. The cast films were annealed at 100° C. and 120° C. for 10 minutes each in a forced air oven to remove residual solvent. Film thickness was measured using a Metricon Prism Coupler 2010 (Metricon Corp.) or PosiTector 6000. Birefringence, optical dispersion and retardation were measured using an M-2000V ellipsometer (JA Woollam Co.).

Examples Example 1: 6-Trifluoroacetyl Substituted Cellulose A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (20 g, 5 wt %). TFA (337 g) was added to another 500 mL graduated cylinder followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the ingredients were mixed with overhead stirring for about 75 minutes. The temperature controller was set to 50° C. and the reaction mixture was stirred for 35 minutes. The reaction mixture was poured into a beaker containing 2000 mL anhydrous diethyl ether to precipitate the crude product. A homogenizer was used to disperse the precipitate to a uniform particle size and the resulting solids were collected by vacuum filtration. The solids were rinsed on the filter with diethyl ether (2 x 200 mL) followed by drying under vacuum at room temperature to give the title product. Analysis: total DS: 1.1, C2DS: 0.03, C3DS: 0.1, C6DS: 1.0 and _Mw : 497,487.

Comparative example 1. Cellulose-6-trifluoroacetate manufactured according to Liebert using microcrystalline cellulose A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. An overhead stir shaft was attached to the top. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Alpha Aesal A17730 microcrystalline cellulose (10 g, 2.2 wt %). TFA (297 g) was added to another 500 mL graduated cylinder followed by TFAA (149 g). The resulting solution was then slowly poured into the reactor. The materials were mixed by overhead stirring at room temperature. After about 2-3 hours, the cellulose was completely dissolved forming a clear viscous solution. The solution was mixed for 1 hour and poured into a beaker containing 1500 mL of anhydrous _Et2O . A homogenizer was used to disperse the precipitate to a uniform particle size and vacuum filtration was used to collect the solids. The solids were rinsed on the filter with diethyl ether (2 x 200 mL) and then dried under vacuum at room temperature to give the title compound. Analysis: Total DS: 1.2; _C2DS 0.08; C3DS: 0.09; C6DS: 1.0;

Comparative Example 1 shows that the Liebert method produces a cellulose ester with low C2 selectivity but high C3 selectivity. Furthermore, the _Mw of the final product is less than half that of Example 1.

Comparative example 2. A cellulose-6-trifluoroacetate 1000 mL jacketed reaction kettle manufactured according to Liebert using Placetate F cellulose pulp was equipped with a removable 4-neck top. An overhead stir shaft was attached to the top. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (10 g, 2.2 wt %). TFA (297 g) was added to another 500 mL graduated cylinder followed by TFAA (149 g). The resulting solution was then slowly poured into the reactor. The materials were mixed by overhead stirring at room temperature. After 3 hours, the cellulose did not dissolve completely, instead a sticky, heterogeneous mass was formed. The mixture was mixed for an additional hour before being transferred to a beaker containing anhydrous Et ₂ O (1.5 L). A homogenizer was used to disperse the material into a uniform particle size and vacuum filtration was used to collect the solids. The solids were rinsed on the filter with diethyl ether (2 x 200 mL) followed by vacuum drying at room temperature to give the title compound. Analysis: Total DS 1.4; C2DS: 0.1; C3DS: 0.7; C6DS: 0.7; M _w : 1,322,504.

Comparative Example 2 shows that the Liebert process is not effective in producing cellulose 6-trifluoroacetate from unmodified softwood pulp. Furthermore, no significant molecular weight loss is observed under these conditions.

Determination of Optimal TFAA Concentration for Acylation of Cellulose The general procedure for determining TFAA concentration is as follows. To the reaction vessel containing cellulose was added TFA and TFAA at room temperature and the reaction was warmed to 60°C. The mixture was stirred until the cellulose was completely dissolved, the temperature was lowered to 50° C., at which time 2.00 equivalents of Ac ₂ O (per anhydroglucose unit of cellulose) was added and the mixture was stirred overnight. Precipitation and polymer separation provided the resulting cellulose acetate.

A summary of these preliminary studies is shown in Table 1. Addition of 0.6 eq of TFAA observed a total DS _Ac of 1.36 with a small amount of esterification at C6. This result indicated selective trifluoroacetylation at C6, although the acylation was not complete. However, we were pleased to find that when 1.6 equivalents of TFAA were used, there was little substitution at C6 and good acetylation was observed at C2 and C3. Next, the effect of additional loading of TFAA was investigated to determine whether trifluoroacetylation was also selective for C2 or C3, although adding 2.6 and 3.6 equivalents of TFAA However, this additional selectivity was not expected. Finally, 1.65 equivalents of TFAA is the ideal stoichiometric ratio for selective trifluoroacetylation at C6, while leaving C2 and C3 open for functionalization. It has been determined.

The results are favorable compared to known methods for the acetylation of cellulose pulp (Table 2). Heterogeneous preparations of cellulose acetates such as Eastman™ CA-320s yield randomly substituted copolymers with acetyl groups distributed at C2, C3 and C6. Cellulose acetate prepared by the formic acid protocol developed by Buchanan (Example 13 of US9243072) provides CA with significantly less substitution at _C6 ( _DSC6 = 0.3). In contrast, polymers isolated by the TFA/TFAA protocol contain virtually no substitutions at C6. For example, the cellulose acetate of Example 2 contains DS=0.05, while the remaining functional groups are concentrated exclusively at C2 and C3. In particular, Example 2 can be prepared at a significantly higher molecular weight than Eastman™ CA 320S or Buchanan Example 13. These data demonstrate the improved quality of cellulose esterification using the TFA/TFAA method.

Example 2: Cellulose 2,3-acetate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (20 g, 5 wt %). To another 500 mL graduated cylinder was added TFA (337 g) followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the ingredients were mixed with overhead stirring for about 75 minutes. The temperature controller was then set to 50° C. and the reaction mixture was stirred for 35 minutes. Ac ₂ O (25.1 g, 2.00 eq) was then added to the reaction mixture over 10 minutes via an overhead addition funnel. The resulting mixture was stirred for 12 hours. After that, the dope was precipitated by pouring into 3000 mL of deionized water to obtain a crude product. The crude product was broken down into uniform particle sizes by homogenization. The crude product was collected by filtration through a frit. The crude product was then suspended in 2000 mL of 5M KOAc (aq.) and slurried for 36 hours. The crude product was collected by filtration through a frit and washed successively with deionized water for 8 hours. The title compound was then dried in a ceramic dish under vacuum at 60° C. for 12 hours. Analysis: Total DS _Ac : 1.9, C2DS _Ac : 0.9, C3DS _Ac : 0.9, C6DS _Ac : 0.05, Mw: 118,627 Da.

By adapting the synthetic procedure to the synthesis of Example 2, Examples 3-5 were synthesized.

Example 6: Cellulose-2,3-propionate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. The reactor was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (20 g, 5 wt %). A TFA/TFAA solution was prepared by adding TFAA (42.7 g) to TFA (337 g). The TFA/TFAA solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the reaction mixture was mixed with overhead stirring (75 minutes). The set point was then set to 50°C. In a separate flask, PrOH (18.26 g, 2.0 eq) and TFA (30 mL) were stirred under _N2 atmosphere. A mixed anhydride mixture was prepared by adding TFAA (51.8 g, 2.0 eq) to the PrOH/TFA solution and stirring the solution (45 min). The mixed anhydride mixture was added via an overhead addition funnel over 10 minutes and the resulting reaction mixture was stirred for 12 hours. The dope was then precipitated by pouring into deionized water (3000 mL) to give the crude product. The crude product was broken down into uniform particle sizes by homogenization. The crude product was collected by filtration through a frit, then the crude product was suspended in 5M KOAc (aq.) (2000 mL) and slurried for 36 hours. The crude product was collected by filtration through a frit and washed successively with deionized water for 8 hours. After drying the material in vacuum (60° C.) for 12 hours, the title compound was obtained. Analysis: DS _Pr : 2.0, C2DS _Pr : 0.8, C3DS _Pr : 0.9, C6DS _Pr : 0.03, Mw: 163,340 Da.

By adapting the synthetic procedure of Example 6, Examples 7-12 and Examples 58-61 were synthesized.

Example 13: Cellulose 2,3-benzoate propionate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (20 g, 5 wt %). A solution of TFA/TFFA was prepared by adding TFAA (41.9 g) to TFA (337 g). The TFA/TFAA solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the reaction mixture was stirred with overhead stirring for about 75 minutes. The temperature controller was set to 50° C. and the reaction mixture was stirred for 35 minutes. _Pr2O (8.02 g, 0.5 eq) was slowly added to the reaction mixture via an overhead addition funnel. During the _Pr2O addition, _Bz2O (41.9 g, 1.50 eq) was added portionwise to the reaction mixture via a solid addition funnel. Both additions were complete after 10 minutes. The reaction mixture was stirred for 12 hours. The dope was then precipitated by pouring into deionized water (3000 mL) to give the crude product. The crude product was broken down into uniform particle sizes by homogenization. The crude product was collected by filtration through a frit. The solids were then resuspended in iPrOH and slurried for 30 minutes. The crude product was collected by filtration through a frit. The crude product was then suspended in 5M KOAc (aq.) (2000 mL) and stirred (36 hours). The crude product was collected by filtration through a frit and washed successively with deionized water for 8 hours. The title compound was obtained after drying in vacuo (60° C.) for 12 hours. Analysis: DS _Bz : 0.9, DS _Pr : 1.0, C2DS: 0.9, C3DS: 1.0: C6DS: 0.0, _Mw : 132,072 Da.

By adapting the synthetic procedure of Example 13, Examples 14-16 were synthesized.

Table 6 provides the degree of substitution for Examples 14-16.

Example 17: Cellulose 2,3-(2-naphthoate)propionate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (20 g, 5 wt %). To another 500 mL graduated cylinder was added TFA (337 g) followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the ingredients were mixed by overhead stirring. After about 75 minutes, the mixture formed a dark orange solution, at which point the temperature controller was set to 50°C. While this method is running, another oven-dried 250 mL round-bottomed flask is charged with 2-NpOH (21.2 g, 1.0 eq) and TFA (60 mL) with magnetic stirring under a nitrogen atmosphere. bottom. TFAA (25.9 g, 1.0 eq) was added slowly to this solution and the solution was stirred for 45 minutes until the slurry became homogeneous. The reaction kettle was then fitted with two separate liquid addition funnels. One funnel was charged with the freshly prepared NpOH/TFAA solution and the second funnel was charged with Pr ₂ O (4.8 g, 0.3 eq). The stopcock of each funnel was opened and the liquid was added over approximately 10 minutes. The resulting mixture was stirred for 12 hours. The dope was then precipitated by pouring into deionized water (3000 mL) to give the product as a white solid. Homogenization broke the solids into uniform particle sizes. Solids were collected by filtration through a frit. The crude product was then transferred to a cellulose thimble and extracted with MeOH using a Soxhlet apparatus for 7 hours. The crude product was then collected, suspended in 5M KOAc (aq.) (2000 mL) and slurried for 36 hours. The crude product was collected by filtration through a frit and washed successively with deionized water for 8 hours. After drying in vacuum (60° C.) for 12 hours, the title compound was obtained. Analysis: DS _Np : 0.7, DS _Pr : 0.6, C2DS: 0.7, C3DS: 0.4, C6DS: 0.07, Mw: 90,003 Da.

By adapting the synthetic procedure of Example 17, Examples 18-20 were prepared.

Table 8 provides degree of substitution and molecular weight information for Examples 18-20.

Example 21: Cellulose 2,3-(2-naphthoate)propionate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (20 g, 5 wt %). TFA (337 g) was added to another 500 mL graduated cylinder followed by TFAA (42.7 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the ingredients were mixed by overhead stirring. After about 75 minutes, the mixture formed a dark orange solution, at which point the temperature controller was set to 50°C. 2-NpOH (25.5 g, 1.2 eq.), PrOH (2.74 g, 0.3 eq.) and TFA (60 mL) were added to another oven-dried 250 mL round-bottomed flask while the method was running. was placed under _N2 atmosphere with magnetic stirring. To this solution was slowly added TFAA (38.87 g, 1.5 eq) and the solution was stirred for 45 minutes until the slurry became homogeneous. The reaction kettle was then fitted with a liquid addition funnel. The funnel was then charged with the previously prepared anhydride mixture. The funnel was opened and the anhydride solution was added to the cellulose dope such that the addition was complete within 10 minutes. The resulting mixture was stirred for 12 hours. The dope was poured into deionized water (3000 mL) to give crude product. The crude product was broken down into uniform particle sizes by homogenization. The crude product was collected by filtration through a frit. The crude product was then transferred to a cellulose thimble and washed with MeOH using a Soxhlet apparatus for 7 hours. The crude product was then collected, suspended in 5M KOAc (aq.) (2000 mL) and slurried for 36 hours. The solids were collected by filtration through a frit and washed continuously with deionized water for 8 hours. After drying in vacuum (60° C.) for 12 hours, the title compound was obtained. Analysis: DSN _p : 1.3, DS _Pr : 0.3, C2DS: 0.9, C3DS: 0.6, Mw: 124,916 Da.

The examples in Table 9 were prepared by adapting the synthetic procedure of Example 21.

Table 10 shows the degree of substitution and molecular weight information for Examples 22-29, 62-65 and 76-81. Acyl 1, Acyl 2 and Acyl 3 are the acyl substituents of Acid 1, Acid 2 and Acid 3 respectively.

Example 30: Procedure for Regioselective C6 Propionylation of 2,3-Substituted Cellulose Esters Freshly dried (22 mm Hg, 50 °C, 12 hours) Example 58 (50 g, 8.9 wt% solids) was charged. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. DMAc (448 g), pyridine (61.6 g, 5.00 eq) and DMAP (1.90 g, 0.1 eq) were added to the flask. The temperature controller was set to 50° C. and the mixture was stirred until the solids dissolved (about 1-2 hours) and the reaction mixture was cooled to room temperature. _Pr2O (27.3 g, 1.35 eq) was then added via liquid addition funnel (2 min). The mixture was stirred at room temperature for 12 hours and the mixture was diluted with acetone (150 mL). The resulting mixture was poured into deionized water (3000 mL). The precipitated crude product was broken down to uniform size by homogenization and the crude product was collected on a coarse frit by vacuum filtration. The crude product was washed on the filter with MeOH (200 mL). The crude product was then washed successively with deionized water at room temperature for 8 hours. The title compound was obtained after drying in vacuo (60° C.) for 12 hours. Analysis: DS _Pr : 1.4 _; DS _Bz : 1.5; C2DS: 0.9; C3DS: 0.9;

Example 31: Regioselective 2,3-Substituted Benzoate/2-Naphthoate Propionate Cellulose A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (20 g, 5 wt %). To another 500 mL graduated cylinder was added TFA (337 g) followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the ingredients were mixed by overhead stirring. After about 75 minutes, the mixture formed a dark orange solution, at which point the temperature controller was set to 50°C. The glass stopper of the reaction kettle was replaced with a plastic funnel and a mixture of Bz ₂ O (27.8 g, 1.00 eq) and 2-Np ₂ O (40.1 g, 1.00 eq) was added portionwise. The reaction was stirred for 12 hours, at which time the dope was precipitated by pouring into 3000 mL of deionized water to give the product as a white solid. Homogenization broke the solids into uniform particle sizes. Solids were collected by filtration through a frit. The solids were then transferred to cellulose thimbles and extracted with MeOH using a Soxhlet apparatus for 24 hours. The solids were then collected and suspended in 5M KOAc(aq.) (2000 mL) and stirred for 36 hours. The solids were collected by filtration through a frit and washed continuously with deionized water for 8 hours. The solids were then dried under vacuum (60° C.) for 12 hours. Analysis: DS _Np : 1.4; DS _{Bz :} 0.6; C2DS: 0.9; C3DS;

By adapting the synthetic procedure of Example 31, the examples in Table 11 were prepared.

example 32
Freshly dried (50 °C, 22.5 mm Hg, 12 h) Example 31 (10 g, 8.9 wt% solids) was added to an oven-dried 500 mL jacketed round-bottom flask with mechanical stirring under _N2 atmosphere. minutes) was loaded. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. DMAc (93 g), pyridine (9.4 g, 5.00 eq) and DMAP (0.29 g, 0.1 eq) were added to the flask and the temperature controller was set at 50° C. to facilitate dissolution of the starting material. Once complete dissolution of the cellulose ester was observed, the reaction was cooled to room temperature at which time Pr ₂ O (0.93 g, 0.3 eq) was added dropwise via syringe over about 2 minutes. The mixture was stirred at room temperature for 12 hours, at which time the reaction mixture was diluted with 100 mL of acetone. The resulting mixture was poured into water (2000 mL) to precipitate the crude product. Homogenization broke the solids into uniform sizes and the solids were collected by vacuum filtration over a coarse frit. The solids were washed on the filter with 200 mL of MeOH (200 mL) followed by water for 8 hours. The solids were then dried under vacuum (60° C.) for 12 hours. Analysis: _{DS Np} : 1.4; DS _Bz : 0.6; DS _Pr : 0.3; C2DS: 0.9;

The examples in Table 12 were prepared by adapting the procedure for the preparation of Example 32.

Table 13 provides degree of substitution and molecular weight information for Examples 33-41.

Example 42. A cellulose 2,3-benzoate 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stir shaft, temperature probe, reflux condenser and ground glass stopper. Reactions were connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. A reactor was charged with Placetate F cellulose pulp (50 g, 5 wt %). To another 500 mL graduated cylinder was added TFA (843 g) followed by TFAA (112 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60° C. and the ingredients were mixed by overhead stirring. After about 75 minutes, the mixture formed a dark orange solution, at which point the temperature controller was set to 50°C. The glass stopper of the reaction kettle was replaced with a plastic funnel and Bz ₂ O (125 g, 1.00 eq) was added portionwise. The reaction was stirred for 12 hours, at which time the dope was precipitated by pouring into deionized water (3000 mL) to give the product as a white solid. Homogenization broke the solids into uniform particle sizes. Solids were collected by filtration through a frit. The solids were then transferred to a beaker containing iPrOH (3000 mL) and slurried for 30 minutes. The solids were then collected by filtration through a coarse frit. The solids were then collected and suspended in 5M KOAc(aq.) (2000 mL) and the mixture was stirred for 36 hours. The solids were collected by filtration through a frit and washed continuously with water for 8 hours. The solids were then dried under vacuum (60° C.) for 12 hours. Analysis: DS _Pr : 0.0; DS _Bz : 1.3 ₍ appeared lower due to lower resolution in NMR solvent); C2DS: 0.8; C3DS: 0.9; C6DS: 0.02;

Example 43. Cellulose 2,3-benzoate-6-propionate Freshly vacuum dried (22.5 mm Hg, 50° C., 12 h) Example 42 (50 g, 8.9 wt % solids) was added to a 1000 mL jacketed round bottom flask under N ₂ atmosphere. Loaded under mechanical stirring. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. DMAc (443 g), pyridine (55.9 g, 5.00 eq) and DMAP (1.73 g, 0.1 eq) were added to the flask and the temperature controller was set to 50°C. The mixture was stirred until the solids dissolved (about 1-2 hours). The reaction mixture was cooled to room temperature and _Pr2O (18.38 g, 1.0 eq) was added dropwise (2 min). The mixture was stirred at room temperature for 12 hours and the reaction mixture was diluted with acetone (200 mL). The resulting mixture was poured into deionized water (3000 mL). The precipitated crude product was broken down to uniform size by homogenization and the crude product was collected on a coarse frit by vacuum filtration. The crude product was washed on the filter with MeOH (200 mL) followed by a continuous stream of water at room temperature for 8 hours. The title compound was obtained after drying (22.5 mm Hg, 60° C., 12 hours). Analysis: DS _Pr : 1.1 _; DS _Bz : 2.1; C2DS: 1.0; _C3DS : ^1.0 ;

Using the preparation procedure of Example 43, the examples in Table 14 were prepared.

Table 15 provides degree of substitution information, molecular weight and glass transition temperature information for Examples 44-57.

Example 67: Synthesis of cellulose 2,3-propionate-6-naphthoate pivalate Freshly dried (22 mmHg, 50°C, 12 hours) Example 60 (20 g, 8.3 wt % solids) was added. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25°C. DMAc (97 g) and pyridine (122 g) were added to the flask. The temperature controller was set to 50° C. and the mixture was stirred until the solids were completely dissolved (about 1-2 hours). The reaction mixture was then cooled to 20°C. In a separate vessel, 2-naphthyl chloride (6.55 g, 0.4 eq) was taken in 15-20 mL DMAc and stirred magnetically. Once the 2-naphthyl chloride was completely dissolved, the solution was added to the dissolved cellulose with vigorous stirring over a period of about 2 minutes. The reaction mixture was stirred at 20° C. for 3-4 hours. After this time, the reaction mixture was charged with pivaloyl chloride (9.31 g, 0.9 eq) over 2 minutes with vigorous stirring. Once the addition was complete, the temperature controller was set to 35° C. and the resulting solution was stirred for at least 12 hours. The reaction was then diluted with acetone (150 mL). The resulting mixture was poured into deionized water (3000 mL) and the precipitated crude product was broken into uniform sizes by homogenization. The resulting solids were collected by vacuum filtration through a coarse frit. The crude product was washed on the filter twice with iPrOH (2 x 200 mL). The crude product was then washed continuously with room temperature deionized water for 8 hours. The title compound was obtained after drying in vacuo (60° C.) for 12 hours.

The examples in Table 16 were prepared by adapting the preparation procedure of Example 67.

Table 17 provides degree of substitution and molecular weight information for Examples 66-73 and 82-88.

Preparation of Example 98:
An oven-dried 500 mL jacketed 3-necked round-bottom flask was transferred to a fume hood and attached to a hood scaffold. The flask was then purged under a nitrogen atmosphere while cooling. The flask was then fitted with a mechanical stirrer and adapter along with a positive pressure of nitrogen. The flask was then charged with Example 89 (20 grams) using a solids addition funnel. DMAc (50 mL) was added to the flask followed by pyridine (150 mL). The reaction temperature was adjusted to 50° C. and the mixture was allowed to stir until complete dissolution of the cellulose ester was observed. The reaction temperature was adjusted to 25° C. and 2-benzothiophenecarbonyl chloride (10.3 g, 0.6 eq) was added over about 2 minutes. The reaction mixture was then held for 3 hours at which time pivaloyl chloride (8.1 g, 0.77 eq) was added dropwise over 2 minutes. The reaction mixture was then warmed to 40° C. and stirred for at least 12 hours. The resulting mixture was then diluted with 100 mL of acetone and poured into a beaker containing 2000 mL of deionized water to precipitate a white solid. Homogenization broke the solids into uniform sizes, and the solids were collected by vacuum filtration through a coarse frit. The solids were washed on the filter twice with 200 mL of iPrOH. The solids were then washed continuously with deionized water at room temperature for 8 hours. The solids were then vacuum dried in a ceramic dish (22.5 mmHg, 60°C) for 12 hours. The product was analyzed by ¹ H NMR, ¹³ C NMR, GPC and CIC. DSBz = 0.29, DSC2 = 0.83, DSC3 = 0.52, DSC6 = 0.96.

The following cellulose esters were prepared by adapting General Procedure B.

Table 19 provides the degree of substitution for the cellulose esters provided in Table 18.

Table 20 provides additional degree of substitution information for Examples 98-103.

Table 21 provides the degree of substitution for Examples 104-109.

Films Table 22 provides films prepared using the General Procedure for Preparation of Films.

The following films shown in Table 23 were prepared by adapting the procedure disclosed above. Films were prepared from the solvent MEK.

Table 24 provides additional properties for the films in Table 23.

CLAIM NOT LIMITED TO DISCLOSED EMBODIMENTS The preferred forms of the invention described above should be used as illustrations only and should not be used in a limiting sense to interpret the scope of the invention. . Modifications to the exemplary embodiments described above may be readily made by those skilled in the art without departing from the spirit of the invention.

Without departing substantially from the literal scope of the invention as set forth in the following claims, the inventors reasonably argue that the present invention pertains to any device outside the literal scope of the invention. We state our intention here to rely on the doctrine of equivalents to determine and assess fair coverage.
(mode)
(Aspect 1)
Regioselections with combined degrees of substitution at C2 and C3 (“(C2+C3)DS)” ranging from about 0 to about 2.0 and degrees of substitution at C6 (“C6DS”) ranging from about 0 to about 0.6 A method for preparing a functionally substituted cellulose ester comprising:
(1) In a reaction medium containing a suitable solvent, cellulose is combined with about 1.4 equivalents to about 1.8 equivalents of trifluoroacetic anhydride (“TFAA”) and about 0.1 equivalents to about 0.8 equivalents of contacting with one or more first carboxylic acids;
where the equivalents of TFAA and first carboxylic acid are based on the sum of cellulose anhydride glucosyl units,
Method.
(Aspect 2)
the first carboxylic acid is R ¹ -COOH;
wherein R ¹ is (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R 2 groups), or 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ⁽ heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl , (C _6-10 )aryl or nitro, and
wherein R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo A method according to embodiment 1, selected from alkyl, (C _6-10 )aryl or nitro.
(Aspect 3)
3. The method of any one of aspects 1-2, wherein the regioselectively substituted cellulose ester has a weight average molecular weight (“M _w ”) in the range of about 50,000 Da to about 500,000 Da.
(Aspect 4)
A method according to any one of aspects 1-3, wherein the suitable solvent is trifluoroacetic acid.
(Aspect 5)
Regioselections with C2 degree of substitution (“C2DS”) from 0.01 to 1, C3 degree of substitution (“C3DS”) from 0.01 to 1 and C6 degree of substitution (“C6DS”) from about 0 to about 0.1 A method for preparing a functionally substituted cellulose ester comprising:
(1) In a reaction medium containing a suitable solvent, cellulose is combined with about 0.5 to about 5.0 equivalents of trifluoroacetic anhydride (“TFAA”) and 0.1 to 2.0 equivalents of one or more secondary contacting with an acylating agent (“FAA”) to esterify at least a portion of the cellulose, thereby producing a regioselectively substituted cellulose ester;
A method wherein the equivalents of TFAA and FAA are based on the total anhydroglucosyl units of the cellulose.
(Aspect 6)
6. The method of embodiment 5, wherein FAA is selected from acid anhydrides or acid halides.
(Aspect 7)
9. The method of embodiment 8, wherein FAA is an acid anhydride.
(Aspect 8)
10. The method of embodiment 9, wherein the acid anhydride is produced in the reaction medium by addition of the carboxylic acid.
(Aspect 9)
FAA is R ^1a -C(O)OC(O)-R ^1b ;
wherein R ^1a and R ^1b are independently (C _1-20 )alkyl, halo(C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _{6- 20} ) aryl (aryl is unsubstituted or substituted with 1 to 6 R ² groups) or contains 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen 5 -20 membered heteroaryl (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups);
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo selected from alkyl, (C _6-10 )aryl or nitro, and
wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 ) 9. A method according to any one of aspects 5 to 8, selected from cycloalkyl, (C _6-10 )aryl or nitro.
(Mode 10)
A method for preparing a regioselectively substituted cellulose ester comprising:
(1) Cellulose in a first reaction medium comprising a first suitable solvent, 0.5-5.0 equivalents of trifluoroacetic anhydride (“TFAA”) and 0.1-2.0 equivalents of contacting with one or more first acylating agents (“FAA”) to esterify at least a portion of the cellulose, thereby resulting in a degree of C2 substitution of 0.01-1 (“C2DS”), 0.01-1 producing an intermediate regioselectively substituted cellulose ester having a degree of C3 substitution (“C3DS”) of 1 and a degree of C6 substitution (“C6DS”) of 0 to about 0.1;
where the equivalents of TFAA and FAA are based on the total anhydroglucosyl units of cellulose,
(2) isolating the regioselectively substituted cellulose ester (“IRSCE”) of said intermediate; and
(3) dissolving said intermediate regioselectively substituted cellulose ester in a second reaction medium comprising a second suitable solvent, from 0.1 to 2.0 equivalents of one or more second contacting with an acylating agent (“SAA”);
A method wherein the equivalent weight of SAA is based on the sum of the anhydroglucosyl units of the IRSCE.
(Aspect 11)
A first suitable solvent is trifluoroacetic acid and a second suitable solvent is methyl ethyl ketone, tetrahydrofuran, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide, dioxane, dimethylformamide, ethyl acetate, 11. A method according to aspect 10, selected from butyl acetate, trichloromethane, pyridine or dichloromethane.
(Aspect 12)
11. The method of any one of aspects 1, 5 or 10, wherein the cellulose is hardwood cellulose, softwood cellulose, cotton linter cellulose or microcrystalline cellulose.

Claims (6)

0 to 2 . A process for the preparation of regioselectively substituted cellulose esters having a combined degree of substitution ( C2+C3)DS at C2 and C3 in the range of 0 and a degree of substitution C6DS at C6 of less than 0.1 , wherein the acyl substituent is Contributing to the (C2 + C3) DS, the C6 DS is the acyl group substitution degree obtained from the first carboxylic acid,
(1) In a reaction medium containing a suitable solvent, cellulose is mixed with 1 . 4 equivalents to 1 . 8 equivalents of trifluoroacetic anhydride TFA A and 0 . 1 equivalent to 0 . contacting with 8 equivalents of one or more first carboxylic acids, said suitable solvent being trifluoroacetic acid;
wherein the equivalents of TFAA and first carboxylic acid are based on the sum of cellulose anhydride glucosyl units,
the first carboxylic acid is R ¹ -COOH;
wherein R ¹ is (C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or 1-6 or ^5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cycloalkyl , (C _6-10 )aryl or nitro, and
wherein R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo A method selected from alkyl, (C _6-10 )aryl or nitro. 2. The method of claim 1 , wherein the regioselectively substituted cellulose ester has a weight average molecular weight (" _Mw ") in the range of 50,000 Da to 500,000 Da. C2 degree of substitution C 2D S from 0.01 to 1, C3 degree of substitution C 3D S from 0.01 to 1 and 0 to 0 . A process for the preparation of regioselectively substituted cellulose esters having a C6 degree of substitution C6DS of 1, wherein the acyl substituents contribute to (C2+C3)DS, i.e. the combined degree of substitution of C2 and C3, said C6DS is the degree of acyl substitution obtained from the first acylating agent FAA,
(1) cellulose is dissolved in a reaction medium containing a suitable solvent at a concentration of 0.05 ; 5 to 5 . Contact with 0 equivalents of trifluoroacetic anhydride T FA A and 0.1 to 2.0 equivalents of one or more of said first acylating agents to esterify at least a portion of the cellulose, thereby producing a selectively substituted cellulose ester, wherein the suitable solvent is trifluoroacetic acid;
where the equivalents of TFAA and FAA are based on the total anhydroglucosyl units of cellulose,
said FAA is R ^1a -C(O)OC(O)-R ^1b ;
wherein R ^1a and R ^1b are independently (C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R 2 groups), or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl ^is unsubstituted or substituted with 1 to 6 R ³ groups);
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo selected from alkyl, (C _6-10 )aryl or nitro, and
wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 ) is selected from cycloalkyl, (C _6-10 )aryl or nitro;
or,
said FAA is R ^1a -C(O)X;
wherein R ^1a is (C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or 1-6 or ^5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo selected from alkyl, (C _6-10 )aryl or nitro;
wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 ) selected from cycloalkyl, (C _6-10 )aryl or nitro, and
The method wherein X is chloro, bromo or iodo . A method for preparing a regioselectively substituted cellulose ester comprising:
(1) Cellulose is treated in a first reaction medium comprising a first solvent with 0.5-5.0 equivalents of trifluoroacetic anhydride T FA A and 0.1-2.0 equivalents of 1 contacted with one or more first acylating agents F A A to esterify at least a portion of the cellulose, thereby having a degree of C2 substitution C 2D S of 0.01 to 1, a degree of C3 substitution of 0.01 to 1; C 3D S and 0 to 0 . To produce an intermediate regioselectively substituted cellulose ester with a C6 degree of substitution C6DS of 1, the acyl substituents contribute to (C2+C3)DS, i.e. the combined degree of substitution of C2 and C3. , said CDS is the degree of acyl substitution obtained from said FAA, said first solvent is trifluoroacetic acid,
where the equivalents of TFAA and FAA are based on the total anhydroglucosyl units of cellulose,
said FAA is R ^1a -C(O)OC(O)-R ^1b ;
wherein R ^1a and R ^1b are independently (C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or substituted with 1-6 R 2 groups), or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen ( heteroaryl ^is unsubstituted or substituted with 1 to 6 R ³ groups);
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo selected from alkyl, (C _6-10 )aryl or nitro, and
wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 ) is selected from cycloalkyl, (C _6-10 )aryl or nitro;
or,
said FAA is R ^1a -C(O)X;
wherein R ^1a is (C _1-20 )alkyl, (C _2-20 )alkenyl, (C _3-7 )cycloalkyl, (C _6-20 )aryl (aryl is unsubstituted or 1-6 or ^5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R ³ groups;
wherein each R ² is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 )cyclo selected from alkyl, (C _6-10 )aryl or nitro;
wherein each R ³ is (C _1-6 )alkyl, halo(C _1-6 )alkyl, (C _1-6 )alkoxy, halo(C _1-6 )alkoxy, halo, (C _3-7 ) selected from cycloalkyl, (C _6-10 )aryl or nitro, and
X is chloro, bromo or iodo;
(2) isolating the regioselectively substituted cellulose ester I RSC E of said intermediate, and
(3) reacting the intermediate regioselectively substituted cellulose ester with 0.1 to 2.0 equivalents of one or more second acyl in a second reaction medium comprising a second solvent ; comprising contacting with an agent S A A ;
A method wherein said SAA equivalent weight is based on the sum of the anhydride glucosyl units of the IRSCE. said second solvent is selected from methyl ethyl ketone, tetrahydrofuran, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide, dioxane, dimethylformamide, ethyl acetate, butyl acetate, trichloromethane, pyridine or dichloromethane; 5. The method of claim 4 . 5. A method according to any one of claims 1, 3 or 4 , wherein the cellulose is hardwood cellulose, softwood cellulose, cotton linter cellulose or microcrystalline cellulose.